Variable: font-encoding-alist

Alist of fontname patterns vs the corresponding encoding and repertory info.
Each element looks like (REGEXP . (ENCODING . REPERTORY)),
where ENCODING is a charset or a char-table,
and REPERTORY is a charset, a char-table, or nil.

If ENCODING and REPERTORY are the same, the element can have the form

ENCODING is for converting a character to a glyph code of the font.
If ENCODING is a charset, encoding a character by the charset gives
the corresponding glyph code. If ENCODING is a char-table, looking up
the table by a character gives the corresponding glyph code.

REPERTORY specifies a repertory of characters supported by the font.
If REPERTORY is a charset, all characters belonging to the charset are
supported. If REPERTORY is a char-table, all characters who have a
non-nil value in the table are supported. If REPERTORY is nil, Emacs gets the repertory information by an opened font and ENCODING.