mail-encode-encoded-word-region
mail-encode-encoded-word-region is an alias for `rfc2047-encode-region' in `mail-parse.el
'.
(mail-encode-encoded-word-region B E &optional DONT-FOLD)
Encode words in region B to E that need encoding.
By default, the region is treated as containing RFC2822 addresses.
Dynamically bind `rfc2047-encoding-type' to change that.