If you plan to manipulate several format tables in the same application,
you may want to give them names. This process is called
registration. You can register a format table with the
register-format-table function. The opposite (un-naming a table,
if you prefer) is done with the
Register TABLE under NAME (a symbol) and return it.
If a table is already registered under that name, FoCus throws a
table-collision error, unless the optional FORCE argument
Unregister NAMEd table.