In order to use custom format strings, you first need to create a
so-called format table. A format table stores mappings between
format directives (represented by their directive characters) and their
intended meaning. In essence, a format table is very similar to a
readtable: it describes how FoCus is to interpret your custom format
strings in order to translate them into standard ones. Creating a
format table is done by calling the function
Create and return a new format table.
The optional argument INITIALLY lets you decide what you want the
table to look like when it’s created. A value of
creates a format table behaving exactly like standard
:standard-upcase do the
same, except that when applicable, only the downcase (respectively
upcase) directive characters are added (See also Casing). Finally,
:blank format table does not contain any directive at all.