A Unicode variation sequence is a special kind of character substitution. Variation selectors provide a mechanism for specifying a restriction on the set of glyphs that are used to represent a particular character. They also provide a mechanism for specifying variants that have essentially the same semantics but substantially different ranges of glyphs.
A variation sequence consists of a base character (or a spacing mark) followed by a single variation selector. The Unicode Consortium maintains three lists with variation sequences:
•Standardized variation sequences.
•Emoji variation sequences. The variation selector character is either U+FE0E (text style) or U+FE0F (emoji style).
•Ideographic variation sequences. The variation selector character is in the range U+E0100 to U+E01EF.
Import and Export
You can import and export Unicode variation sequences, using this format:
Base Selector GlyphName
for example:
$3515 $FE00 CJKCOMPATIBILITYIDEOGRAPH-2F824
Note: User defined variation sequences are not valid. If you are in need of a custom substitution, then you can most likely use glyph substitutions which are part of OpenType layout features.
More information about variation sequences and the lists can be found here: