1. Linguistic records represent the most valuable sources when studying the early history of the Hungarian language. The era offering such records with regard to this language spans a millennium. When conducting research on the earliest period, we can primarily rely on Latin charters that also include vulgar (Hungarian) language elements (mostly toponyms and personal names). These charters make up the first remnants of Hungarian written culture using Latin script. They include founding charters, charters of donation, estate and asset surveys, border charters, etc. (cf. Hoffmann et al., 2017, 71–72).

1.1. In diplomatics, charters are categorized into different groups based on the form in which they have survived and their reality content. Based on the form of survival, a charter may be deemed an original (originale), a copy (copia) or a draft (minuta). Two or more original charters could be created simultaneously with the same text. The copies may be authentic (copia authentica), in which case the person making the copy guarantees the authenticity of the copied charter, or they may be simple copies (copia simplex). In terms of text reproduction, there are full and partial copies. Besides these, it was also a tradition in Hungarian medieval charter writing for former charter texts not to be included verbatim; only their substantive parts being used instead. The copied documents often did not survive independently but only as parts of collections. Based on their reality content, diplomatics distinguishes between authentic and forged charters (Giry, 1894, 6–36; Szentpétery, 1930, 1–8, 244–249; Érszegi, 1986, 13–14; Solymosi, 2001, 153–157, 2006, 9–13).

Moreover, within diplomatics, different types of forged charters have been identified. The classification of charters into different types is also of key significance for the success of linguistic studies. Forgeries differ from each other to a great extent in terms of the extent of forgery, its age, objective, as well as its success. Based on these factors, complete and partial forgeries are distinguished from each other: they may be of the same age, they may gave been issued at the time indicated on the forged charter, some may come from a later date may be from the modern era. There were also forged charters written in order to provide legal benefits and others issued out of social or scientific vanity. In terms of their success, we need to include both those that can disguise their falsehood well and those that are less successful in this respect (cf. Szentpétery, 1930, 252–253).

When discussing the extent of forgery, experts of the field fundamentally classify these documents into four large groups. 1. The text of an authentic charter was copied in a way that formerly non-existent parts were inserted into it, thereby creating interpolated charters. 2. There are forged charters that are true in terms of their form but are partly or completely forged in terms of their content. 3. The opposite of the previous type also exists, i.e. there are formally forged documents that are true to their original content. Charters of this type were usually made so as to replace lost documents. 4. The last group comprises completely forged documents (both with regard to their content and form) (Szentpétery, 1930, 7, 252–253; Érszegi, 1986, 13–14; Solymosi, 2001, 156, 2006, 12).

From a linguistic perspective, it is better to merge these four types into two larger ones: charters that are partially or fully forged with regard to their content. In terms of linguistic analysis, it is of no special relevance whether a completely forged charter text was made in a formally authentic or forged manner. At the same time, the charters that are only formally forged may be included under authentic charters when studying Hungarian language elements, as the texts of these charters did indeed record existing linguistic conditions (cf. Szőke, 2018a, 429–430).

1.2. We only have a few charters from the earliest history of Hungarian charter writing in the 11th century. From the three centuries of the Árpád Era (1000–1301), we are aware of 4,419 charters of different statuses (authentic, forged, original, copy). A mere 4% or so of these (198) come from the 11th and 12th centuries, while the remaining 4,221 are from the 13th century (Solymosi, 2006, 206–207).

There are several reasons why the number of Hungarian sources dating to the 11th century is so low. Firstly, there were far fewer documents issued in this early stage of Hungarian written culture and, secondly, a part of the recorded charters were destroyed over time. We know of only four authentic charters from this century that survived in their original form (cf. DHA. 1, 144–152, 225–226, 264–265, 295–301). Besides these, the majority of Hungarian charters from the 11th century survived in copies (made in later eras). It has been shown about another significant part of charters dated in this century that they were issued later – even centuries later. What is more, in several cases these charters were forged in such a way that their 11th century texts were interpolated centuries later. György Györffy mentions 115 charters from the 11th century in his work on the subject (Diplomata Hungariae Antiquissima, DHA) which includes a critical edition of early charters, thus the authentic documents which have survived in their original form from a millennium earlier represent less than 4% of the Hungarian charters known today.

It is due to this unfavourable circumstance that besides the 4 charters mentioned above, we also include the non-authentic and non-original charters of the 11th century in our research. Disregarding these sources would deprive Hungarian scholarship in historical linguistics of a large group of source material.

2. It has been a long-held view that studies in historical linguistics may rely only on the onomastic corpus of authentic charters (and maybe copies) that have survived in their original form, as these are certainly the most valuable from the perspective of research in historical linguistics. The monographic study of Hungarian linguistic records is usually linked to the 20th century, but there was a work published as early as the end of the 19th century that analysed the Hungarian-language elements of a charter from a linguistic perspective (Szamota, 1895). The first truly linguistic monograph on the Founding Charter of Tihany, the oldest authentic charter that has survived in its original form in Hungary, was written in the middle of the 20th century (Bárczi, 1951). Some other works had been published even before this foundational linguistic work that has served as a model to this day, but they were less detailed (Mikos, 1935; Szabó, 1954; Pais, 1939; Kniezsa, 1939, 1947–1949; Terestyéni, 1941; Gácser, 1941; Galambos, 1942). In the second half of the century, these works were pushed into the background by studies of old Hungarian texts, and only a few studies focused on charters (K. Fábián, 1997; Mollay, 1982, 93–119).

At the beginning of the 21st century (in 2005, cf. Érszegi ed., 2007) the 950th anniversary of the writing of the Founding Charter of Tihany gave a great impetus to research on charters. Besides shedding more light on the Founding Charter of Tihany (cf. Zelliger, 2005; Hoffmann, 2010a; Szentgyörgyi, 2014), the anniversary also affected the processing of other charters. Several researchers began to assess or reassess some of the early Hungarian charters (e.g., Szentgyörgyi, 2012; Mozga, 2014; Kovács É., 2015, 2018; Szőke, 2015).

Increasing interest in Hungarian research into historical linguistics over the past one or two decades has also had a beneficial impact on the linguistic analysis of groups of charters that had previously been in the background. Due to this change of approach, researchers are relying on the onomastic corpus of non-authentic charters and on charters that have not survived in the original form more extensively than before.

In Hungarian research in historical linguistics, these charters are referred to as charters of an uncertain chronological status (Szőke, 2015, 16). This is not synonymous with the terminology of charters with a suspicious or dubious credibility as used in diplomatics. In this case, these terms are used for charters that have raised suspicions in connection with their external appearance or the content of certain parts, but forgery cannot be proved beyond doubt (Solymosi, 2001, 157).

The phrase charter of uncertain chronological status means that the linguistic assessment of the toponyms in authentic charters that have survived in copies is just as uncertain as that of forged charters. In the process of copying, the text might have been modified (for example, the spelling of proper names could be modernised), but this was not obligatory and therefore it is difficult to decide if the recording of various linguistic elements belongs to the era of writing the original charter or that of the copy (cf. Kenyhercz, 2016).

The situation of forged charters is similar: it does not matter if we know that a charter was recorded in the 13th and not the 11th century, and we cannot assess the spelling of the linguistic elements included in it as a tradition of the later century overall. Forgers used charters that had been issued in the same subject as the forged charter as sources, so that they would fit into the (authentic) charters of the forged era (Kniezsa, 1928–1929, 190; Jakubovich and Pais, 1929, XXV). The copying of patterns is also visible in the recording of vulgar linguistic elements. Therefore, the linguistic attributes of a minimum of two eras are also present in the texts of forged charters (cf. Szőke, 2016, 53–54, 2019a, 2019b, 2019c, 101–103). In the case of interpolated charters, a special type of forged charter from the perspective of diplomatics and linguistics-philology, the authentic, original and subsequently inserted forged parts became parts of the process of copying the charter. Thus, when analysing the authentic parts of an interpolated charter, we can examine the charter as a copy. The study of subsequent additions resembles the linguistic research conducted on forged charters (Szőke, 2015, 18–19, 56–57).

The linguistic analysis of Hungarian charters of an uncertain chronological status was also significantly hindered in the past by the lack of critical editions of charters. The critical approach has been present in the Hungarian scholarly mindset since the end of the 19th century (e.g., Fejérpataky, 1878, 1892, 1895; Karácsonyi, 1902; Szentpétery, 1918, 1923, 1938), and yet the publication of the first critical charter collection took a long time. The Hungarian Academy of Sciences planned to publish such a work as early as the middle of the 20th century (Györffy, 1960, 525; DHA. 1, 5.) but in the event this did not take place until decades later in 1992, when the 1st volume of Diplomata Hungariae Antiquissima (DHA.) was published with György Györffy as editor.

Of the charters of uncertain chronological status, István Hoffmann (2010b) and Rita Póczos (2015, 2017) studied the Founding Charter from Pécs from 1009 which has survived after being copied multiple times. Of the interpolated charters, it was the Charter of Garamszentbenedek that was first analysed (Szőke, 2006, 2015). Besides the analysis of the toponyms of the charter, I also considered it important to identify such clues (mostly in historical linguistics and philology) that may help the analysis of other charters with a problematic status as well (Szőke, 2015, 37–82).

Increasingly extensive inclusion of charters of uncertain status in research in historical linguistics is also indicated by the fact that most recently two such 11th century charters have caught the attention of researchers: Éva Kovács (2018) is working on the Founding Charter of Százd (1067), while Katalin Pelczéder (2015, 2018) is examining the source value to historical linguistics of the Bakonybél Survey (1086). Besides the interpolated charters forged in some of their details, research of completely forged charters conducted on basis of linguistic features has also started. Due to their early dates, charters of this status that have survived under the name of the first Hungarian king, Saint Stephen (1000–1038), have proved to be the most adequate sources (Szőke, 2016, 2019a).

3. It might be revealed about certain charters of an uncertain status that they are not suited to be used for studies in historical linguistics. Both the completed and the ongoing analyses seem to indicate, however, that these charters may significantly increase the number of sources in historical linguistics. Even if the historical linguistic status of certain charters cannot be fully ascertained in the process, there will be some proper names in these texts whose chronological features can be identified. The expansion of authentic name occurrences related to the 11th century, even if offering only single pieces of data, certainly has a great benefit for better understanding this era with such a scarcity of sources.

These linguistic records cannot be analysed using the same methodological principles as we employ for authentic and original charters, and thus their study requires new approaches (cf. Szőke, 2015, 7, 21–22).

Works in history and diplomatics mention several factors with the help of which the different chronological layers of charters may be successfully separated from each other. The legal affairs of abbeys, for example, indicate clearly which of the names of the forged charters belong to the remnants of the age of forgery. If the abbey started litigation in connection with the donation included in the forged founding charter, then this donation probably did not belong to the abbey at the time of foundation. The comparison of forged founding charters and the subsequent estate and donation survey charters of abbeys may also be successful (see Szőke, 2017, 141–143). When defining the chronological layers, the formulas of the charters also serve as crucial clues, since this feature of charters parts changed a great deal between the 11th and 13th centuries. The stylistic features of the charters, for example their choice of words, may also serve as an indication for the later creation of parts of charters. The different types of donations may also serve as proof against the authenticity of the given section. For example, it may be suspicious if customs are donated in areas that were scarcely populated in the 11th century (see Szőke, 2015, 39–41, 2016, 49–50).

The aspects listed above may be used best when defining the source value of names in historical linguistics. With their help, we can most probably identify those toponyms that were already included in the original source which served as a basis for writing the forged charter, as well as the original version of the interpolated charter. They are less helpful when analysing the names which were probably not included in the original charter from the perspective of historical onomastics, as irrespective of this fact, the places and the names may already have existed in the 11th century. These aspects can also be used, to a lesser extent, for the historical linguistic analysis of toponyms in themselves (cf. Szőke, 2019d, 312–313).

4. In the following, I will discuss those methodological principles and study approaches that may facilitate the linguistic analysis of charters of an uncertain chronological status and thus the identification of their source value in historical linguistics. Although these are defined based on charters from Hungary, due to their universal nature, a significant portion of them may also be used successfully with regard to other regions of medieval European charter writing.

4.1 We start our introduction of the different methods, with close references to those mentioned above, by discussing why the source value of charters of uncertain chronological status must be separated for historical toponomastics and historical linguistics.

In the case of copies, the chronological layers refer to different sub-areas of language history, meaning that the names of the original charter and the name forms of the copy may differ from each other in their spelling and phonological features. In many cases, however, these phenomena cannot be clearly connected to the age of the original charter or that of the copy. The existence of the names, however, may be rightfully supposed both with regard to the age of the original charter that did not survive and that of the creation of the copy.

At the same time, in the completely or partly forged documents, there may also be toponyms that had not yet been present in the forged charter (if there was one). Therefore, in these types of charters with a questionable authenticity, we may distinguish between two types of chronological levels. Thus, we first need to establish whether the particular toponyms were included in the original charter and whether they had existed at the time for which the charter was forged, or were added to the text only as a result of the forgery itself. Only after this question is settled, may the toponyms be associated with the chronological layers defined based on the principles of historical linguistics. Thus, prior to identifying their source value in historical linguistics, these charters need to be examined as sources in historical toponomastics.

The historical linguistic assessment of the forged charters (or charters containing forged sections) cannot be performed automatically even if we think we know which parts of the charter are authentic and which are forged. It would be a mistake to mechanically associate the parts of the charters considered to be authentic to the 11th century from a historical linguistic perspective, while the forged parts would be linked to the age of forgery. Even when analysing the parts that are clearly from the 11th century in texts recorded later, we need to be suspicious about the toponyms which were written differently at the time of subsequent recording, in the process of forgery, i.e. that were adapted to contemporary pronunciation and, mostly, to the writing traditions of the era. At the same time, certain elements of the sections newly created at the time of forgery (for example, where 11th century sources were available for scribes of charters as models) might be closer to 11th century forms, precisely in order to disguise the act of forgery itself (Szőke, 2015, 56–57, 81–82).

In the case of some charters, there may be as many as 4 or 5 chronological layers from the perspective of historical linguistics, but in many cases it is more expedient to treat them together. By analysing charters forged back to the 11th century, we primarily try to find out to what extent the toponyms include 11th century attributes despite forgery taking place at a later time, i.e. to what extent they can be used as sources for the linguistic characterisation of the 11th century. For example, the Charter of Pécsvárad, forged back to the age of St. Stephen (1015), is dated as follows: +1015/+1158 [1220 k.]/1323/1403/PR. (DHA. 1, 63). Instead of the 5 chronological layers that may be supposed based on this dating (11–15th centuries), in our analyses we consider only three (11th, 13th, 15th centuries). The charter dated back to the age of St. Stephen (1015) and the copy of the Charter of Géza II (1158) may both have been recorded in the first part of the 13th century, while although the copy made in the 15th century was preceded by one in the 14th (1323), it is not significant from the perspective of the identification of early (11th century) features whether the given form originates from the 14th or 15th century (cf. Szőke, 2019b, 107).

The specification of the date of creation of charters of uncertain chronology has also received increased international attention since the end of the 20th century. The DEEDS (Document of Early England Data Set) database was launched at this time at the University of Toronto in order to develop a computer-based method for the determination of the chronological features of a large number of undated English language charters. The program associates charters that have survived without a date with a certain time based on formulas and word patterns occurring in the text of charters including authentic dates (Gervers, 2000; Fiallos, 2000; Gervers et al., 2012). The method significantly facilitates the determination of the date of recording of forged charters, as well (cf. Gervers et al., 2012, 1638.), even though it does not provide clear results for all types of forged charters. For the time being, it may be used successfully in cases where the forger did not strive to adapt to the norms of the age for which the charter was forged (Declercq, 2000, 132–133). In the case of forged charters, however, it is difficult to decide to what extent the forger relies on the original text serving as the basis of the forgery and to what extent to the standards of their own time. Thus, for the time being, this computer-based method does not facilitate the analysis of charters of an uncertain chronological status in Hungary, but thanks to expected future developments, with time it will also become possible to use it for this purpose (cf. Szőke, 2020c).

4.2 The linguistic study of charters usually cannot take place without using and building on the results of related disciplines (especially those of history and diplomatics), and this is even more so in the case of charters of uncertain status. In fact, the critical editions of the charters themselves make it possible for us to analyse these charters in linguistic terms.

These publications discuss in detail, among other things, the philological features of the documents, as well as the circumstances of their creation and their objectives. It is especially important to be aware of these factors if we wish to be able to interpret accurately the onomastic corpus of the charters. Thus, before linguistic analysis, we need to understand what experts in the fields of history and diplomatics think about the analysed charters as historical sources.

For example, in connection with the forged charters dated to the beginning of Hungarian written culture, it should also be considered that the dominant status of oral culture throughout the centuries may also have had a negative impact on the written records of monastery foundations. In many cases, the fact of foundation was not recorded in writing, or the document created at the time of the foundation included only a part of the donations (Fügedi, 1991, 39–40). If, however, a dispute over such a donation emerged later on, the lack of a written document had to be made up for in order to settle the dispute successfully. To make up for such a lack of documentation, it was common to resort to illegal means, meaning that forged charters were issued or the text of the existing charter was amended with the privileges that had not been originally included. Even the strict laws enacted against the creators and users of forged charters proved unable to stop this practice (cf. Szentpétery, 1930, 249–250).

Thus, forgery did not necessarily mean that they wanted to acquire donations that they did not originally possess. In many cases, what happened was that they could not verify their entitlement with documents because at the time of acquiring the donation it was not a widespread tradition to record the fact in writing. In other cases the forged charters were created in order to make up for charters that had formerly been issued but were subsequently lost (cf. Szentpétery, 1930, 254; Szovák, 2001, 37). Thus, the vulgar toponyms of such a charter (section) may be used as fully fledged sources in historical toponomastics for the forged age (the 11th century), and their recording could also feature the orthographic and phonological norms of this early era (cf. Szőke, 2019a, 2019b, 2019c, 101–103).

4.3. It is not enough to distinguish the charter with an uncertain status from the authentic, original charter – we also need to classify charters further within this group, as their status may be uncertain in a range of different ways. For example, the copies and the interpolated charters were produced based on the original charter. There are also some forged charters that were written based on one or more authentic charters, but even in such cases the forgers did not copy fully the text of the authentic charter. In many cases, the forged documents were not even issued in connection with the same case as the charters used as sources for their writing (Szőke, 2018a, 427–428).

It has become obvious during the analysis of the Founding Charter of Garamszentbenedek that it was not enough to distinguish the subsequently inserted, interpolated charter parts from the sections also included in the original. For a more precise analysis of the remnants, we need to draw further distinctions between the subsequent interpolations. For example, it is also of key significance for the linguistic analysis of toponyms to be aware of the level of forgery, i.e. what information was added to the charter in the process of interpolation. Thus, if we examine interpolated names not in a uniform manner, but in line with the inserted text types, then the different levels of interpolation may serve as different clues for specifying the source value of names in historical linguistics and toponomastics.

We differentiate between two main types of interpolated texts: there are interpolations that are relevant from the perspective of historical linguistics and there are those that are linguistically irrelevant. I include in this latter group all subsequent additions that do not include toponyms, i.e. linguistic elements that could serve as the basis of historical linguistic analysis. Within the group of interpolations which include vulgar toponyms, I specified 5 types. These types of interpolations cover the following categories: 1. interpolated toponyms that are also included in the authentic, original parts of the charters; 2. short interpolations following one another in list form; 3. interpolations occurring in the name body of remnants; 4. the interpolated boundary descriptions of authentic estate donations; 5. interpolations covering a part of authentic boundary descriptions of authentic estate donations (Szőke, 2015, 66–77, 2020c).

4.4 When editing both the substantive and formulary parts of the charters, the scribes usually used different documents as models, as I have already noted above. These included notes that featured substantive data or the formula books compiled from model charters. If charter(s) had already been issued on the subject of the charter to be made, the writer of the charter could also rely on these (Szentpétery, 1930, 25). In the case of the charters surveying the estates of abbeys, for example, the use of the formerly written founding charter as a source is clearly identifiable. The writing of forged charters could follow a similar process (Szentpétery, 1930, 255.) indeed, in such cases the scribe might have been even more in need of borrowings from the text of genuine charters. This could help them in disguising the marks of forgery. In many cases, however, it was precisely the matching elements in different charters that made a forged charter suspicious.

This feature of charter writing must not be disregarded by linguistic studies, either. We may only hope to accomplish successfully the analysis of charters of uncertain status from the perspective of historical linguistics if the charters are assessed in the full awareness of the texts used for their production. Studying associated charters together can render it easier to distinguish the linguistic layers present in the forged charters (e.g., Szőke, 2016, 53–54, 2017, 141–148).

Previously, it was believed that forged charters were unreliable sources for studies in linguistics mostly because their writers recorded a lot of archaic forms based on former charters (Kniezsa, 1928–1929, 190; Jakubovich and Pais, 1929, XXV; Szentpétery, 1930, 253). I, however, believe that using charters from the forged era as models may significantly facilitate the evaluation of forged charters. If the source of a forged charter was a charter deemed reliable from the perspective of historical linguistics, then the comparison of linguistic elements featured in both charters (in the forged charter and its source) may also contribute to the distinction of elements belonging to different eras (cf. Szőke, 2017, 141–143).

4.5. Forgeries (from Hungary) include groups of charter whose elements were not created at the same time, but the substantive and personal links between them and the forgery, which often occurred at the same place, resulted in correspondences in their structure and these render their joint analysis considerably easier (cf. Szentpétery, 1930, 255). This is also why I have chosen to work on four forged charters of Hungary's King St. Stephen in my research, where these four (the charters of Bakonybél, Pécsvárad and two of Zalavár) constitute a unified group within a total of six forged charters that have survived with the name of the first Hungarian king. The abbeys of Bakonybél, Pécsvárad and Zalavár were all founded by the first Hungarian king and besides other sources they all relied on the foundation charter of Pannonhalma, also related to St. Stephen (cf. Szentpétery, 1930, 255–256).

4.6. When analysing Hungarian charters from the perspective of historical linguistics, in recent decades researchers did not remove the proper names from the Latin text but, following in the footsteps of Loránd Benkő (1998, 114–115, 2003, 70), examined them within their textual context (see Hoffmann, 2004; Szőke, 2013, 2015, 120–148, 2018b; Szentgyörgyi, 2014, 82–93; Kovács, 2015, 193–196, 2018, 97–105; cf. Hoffmann et al., 2018, 39–97). The exploration of procedures used by drafters of charters is especially important from the perspective of judging the morphological form of the toponymic data, i.e. the study of contemporary forms in living language (cf. Hoffmann, 2006, 142). At the same time, such an analysis of charters of uncertain chronological status may also bring additional benefits: it can help with the differentiation of the chronological layers of charters. The “poor” textual context of Hungarian toponyms of the Founding Charter of Pécsvárad – for example, the absence of Latin geographical common nouns indicating the type of place designated by the name (e.g. fluvius ‘river’, mons ‘mountain’, villa ‘village’) – can probably be interpreted as a “remnant” of an 11th century charter (from the age of St. Stephen) (Szőke, 2020b). The low number of names in Latin compared to all the designations of the founding charter and the use of vulgar elements instead of Latin also indicate recording in the 11th century (Szőke, 2020a).

4.7. The general perception in connection with charters of uncertain status from a linguistic perspective is that these sources can only be used to answer questions in historical phonology and historical orthography in a very limited way. It was partly because of this approach that Hungarian remnants were pushed into the background in linguistic research for such a long time (cf. Hoffmann, 2007, 16, 2010a,b, 77, 2020, 386). Study of these charters with the above objectives requires far more thoroughness, but I still believe that, at the time of specifying their chronological features, we should not fully refrain from considering their historical orthographic and phonological features.

The roots of modern Hungarian historical orthography (Kniezsa, 1952) and phonology (Bárczi, 1958a) reach back to the mid-20th century. Although excellent summaries have been made since this time in both fields (Korompay, 2018; E. Abaffy, 2003; Gerstner, 2018), by extending these analyses to a larger group of data (for example, by including the onomastic corpus of non-authentic and non-original early remnants) new knowledge may emerge. Géza Bárczi already noted in the middle of the 20th century that the study of charters from the first centuries of Hungarian written culture may fundamentally alter our knowledge of historical phonology and orthography (1958b, 144).

5. The key findings of the present paper may be summarised as follows. The number of authentic and original charters surviving from the 11th century, the first period of Hungarian charter writing, is low. Therefore, in recent decades charters of uncertain chronological status (that have not survived in their original form and are not authentic) have received growing attention in Hungarian historical linguistic research (whilst acknowledging that charters that have survived in the original are beyond doubt the most valuable sources for studies in historical linguistics).

Due to the circumstances of their creation and survival, they may be assumed to contain multiple chronological layers, thus their linguistic exploration requires a different set of approaches than that of authentic charters. The methods introduced in the paper have emerged while analysing Hungarian charters, but due to their universal relevance they are most probably also applicable in other fields of the study of medieval European charter writing.

1. One of the most important principles of analysis is that the source value of toponyms in charters of an uncertain status needs to be studied separately in the case of historical onomastics and historical linguistics. First, in connection with the toponyms of the charters we need to clarify whether the particular names may already have been included in the original charter or the charter used as a basis for the forgery, and whether they may already have existed at the time for which the document was forged (historical onomastic source value). Establishing the historical linguistic source value of the names may only follow subsequently. This is because we should look for historical linguistic signs of the 11th century in the case of names with an 11th century historical linguistic source value.

2. The linguistic analysis of charters may only be successful if it relies heavily on the results of related disciplines. In fact, the critical editions of charters themselves make it possible for us to analyse these charters of uncertain chronological status as linguistic records.

3. To ensure their successful analysis, we should further classify charters within the group of charters of uncertain status as their status may be uncertain in a number of different ways and this may necessitate a stronger focus on certain aspects.

4. We may gain more information if we assess the documents within the network of charters issued earlier and used for their creation.

5. Diplomatics specifies groups of (Hungarian) forged charters based on material and personal connections, as well as on their often shared place of forgery. It is important that in the process of analysing forgeries within the same group we should also focus on the other forged charters of the group to a greater extent than customary.

6. A relatively new procedure which may also contribute to the successful distinction of the chronological layers of the charters analyses the vulgar language elements not independently of the Latin text, but as its integral parts, also paying attention to their direct Latin context.

7. The study of toponyms included in charters of uncertain status from the perspectives of historical phonology and orthography requires great care but analyses so far have indicated that these charters may also be suitable for the careful consideration of such questions.

The linguistic analyses carried out to date based on the ideas presented above (e.g., Szőke, 2015, 37–148, 2017, 141–148, 2019c, 101–103; Kovács É. 2018, 29–96.) have confirmed the preliminary supposition that total neglect of charters of uncertain chronological status in historical linguistic research is not justified and that these charters may be studied with great care using these new methodological principles. If we continue to move in this direction and study even more charters of uncertain status linguistically, we may gain new insights into 11th century Hungarian language by further expanding the already enriched linguistic corpus dated for the 11th century (cf. Hoffmann, 2020, 387).