+ is a list of font-entities. The font properties to be considered
+ are: :foundry, :family, :adstyle, :registry, :script, :lang, and
+ :otf. See the function `font-spec' for their meanings. Note
+ that the last three properties are stored in FONT_EXTRA_INDEX
+ slot of FONT_SPEC.
+
+ The returned value is a list of font-entities. Each font-entity
+ has :type property whose value is the same as the above `type'.
+ It also has these properties if they are available from the
+ corresponding font; :foundry, :family, :adstyle, :registry,
+ :weight, :slant, :width, :size, :dpi, :spacing, :avgwidth. If
+ the font is scalable, :size and :avgwidth must be 0.
+
+ The `open' method of the same font-backend is called with one of
+ the returned font-entities. If the backend needs additional
+ information to be used in `open' method, this method can add any
+ Lispy value by the property :font-entity to the entities.
+