Ulpf42

The base64 string at bottom translates to "http://www.unicode.org/charts/".

Going by the existing characters, the first table is Cyrillic, the second table is Greek and Coptic, and the third table is Latin Extended-B

The sigil positions, in order, correspond to: Take last two as ascii chars and..
 * 1) U+0378 undefined
 * 2) U+0248 Ɉ
 * 3) U+0458 ј
 * 4) U+0463 ѣ
 * 5) U+0468 Ѩ
 * 6) U+0231 ȱ

https://i.cubeupload.com/xHXch1.png