The research of birch bark manuscripts, which was conducted by A.A. Zaliznyak
D. Sichinava, "Birch bark manuscripts: the retelling of Academician Zaliznyak's lecture". 2017. Autotranslation.
Most of the manuscripts belong to the XIV century, only two of them are pre-Mongol and date back to the XII century. Among them is manuscript No. 1091: it is only a list of names and terms of kinship ("wife", "mother", "stepmother"); the list includes equally men and women (rare gender equality for ancient manuscripts) — perhaps gathered for someone's christening. However, it is truly remarkable that scientists already knew two of the characters from this list. Firstly, this is a woman Yanka, the author of a very colorful msnuscript No. 731, found in the early 1990s (and when found broken into a dozen pieces with a shovel): there she turns to the matchmaker Yarina with the news that her son agrees with the proposed candidacy of the bride. And the second character — Yakim — wrote not one, but as many as 37 manuscripts, mostly discovered in the 2010s. The manuscript No. 1091 itself is interesting because all the words in it are separated by vertical dashes. In the Old Russian (and in general Eastern Christian) book writing for a long time it was not customary to divide the text into words — neither spaces, nor dashes, nor anything else: the entire text was written in a row; it began to be divided into words in Russia only with the advent of printing. However , in birch bark manuscripts, the division into words sometimes comes across: this may be due to some Western European influence.
From the manuscript No. 1096, only the address formula remains: this is a fragment of a letter from Klimenty and from Marya to Pytok Oparin. The name and patronymic of the addressee are also two nicknames: pyatko means "the fifth child in the family", and sourdough means "fermented dough"; as explained by Zaliznyak, this is probably a hint of a person's complexion. This fragment, however, becomes much more interesting if we recall the previously found letter No. 311: in it, the peasants ask the feudal lord to rid them of the new owner of the village named Klimets Oparin, who is "not a neighboring person" for them. Klimets is, of course, the same as Klimentiy, so manuscript No. 1096 is most likely a family correspondence between two Oparin brothers. Previously, there were samples of such family correspondence of other people, including invitation to visit, a notice of a wedding, etc.
Manuscript No. 1098 is not so peaceful: this is a very frequent genre among birch bark manuscripts — a threat to a debtor. Terentyi complains to Anton and Moisey that after three warnings they did not send him any money that they owe, they also did not send fish. The creditor sets the payment deadline for debtors — Sunday — and warns that in case of non—payment, an official collector, the so—called "birich", a junior authorized official, will come for them.
You can read the full article in Russian here: https://arzamas.academy/mag/469-beresta