Borrowing from the "Belarusian" chronicle
After the "Tale of Švitrigaila" in "Vytautas" chronicles placed a shortened version of the Smolensk chronicles, which borrowed from the "Belarusian" tradition. Details about this – in a separate section. It shows that more detailed borrowings were made in Vit4L and reduced – in Vit6L and subsequent "Lithuanian" chronicles.
At the same time (in the middle of the 15th century, after 1446), during the final arrangement of Vit4L, chronological gap between the end of "Acts of Vytautas" in 1397 and the Congress rulers in 1430 was filled with extracts from the annals of the "Belarusian" tradition.
It is easy to notice that the source of records Vit4L + Vit6L – this is our good friend Bil0L (Table 16 rows).
It is easy to see that all records Vit4L and Vit6L are complete borrowings or shortenings of Bil0L, including such exotic as the episodes 13 – 14, which are not found in any other chronicle (more – in the section "Annals of Metropolitan Photius").
In terms of content, these extracts from Bil0L very homogeneous – all of them are centered around the person of Vytautas. Author Vit4L without did not have his own material to fill said gap, took advantage of the fact that he had found in Bil0L. One record (15) regard to Švitrigaila, who’s early biography was also unknown to the author.