- Mbstring: . Use of QPrint, Base64, Uuencode, and HTML-ENTITIES 'text encodings' is deprecated for all Mbstring functions. Unlike all the other text encodings supported by Mbstring, these do not encode a sequence of Unicode codepoints, but rather a sequence of raw bytes. It is not clear what the correct return values for most Mbstring functions should be when one of these non-encodings is specified. Further, PHP has separate, built-in implementations of all of them; for example, UUencoded data can be handled using convert_uuencode/convert_uudecode.
From https://github.com/php/php-src/commit/9308974f8cc6c1046f228be5320fe067913ba987
Codesearch (best-effort): https://codesearch.wmcloud.org/search/?q=mb_%5Cw%2B%5Cs*%5C(%5B%5E%22%27%5D*%5B%22%27%5D(BASE64%7CHTML-ENTITIES%7CHTML%7CQUOTED-PRINTABLE%7CQPRINT%7CUUENCODE)%5B%22%27%5D&i=fosho&files=%5C.php&excludeFiles=&repos=