custom-add-frequent-value

custom-add-frequent-value is an alias for `custom-add-option' in `custom.el'.

(custom-add-frequent-value SYMBOL OPTION)

To the variable SYMBOL add OPTION.

If SYMBOL's custom type is a hook, OPTION should be a hook member.
If SYMBOL's custom type is an alist, OPTION specifies a symbol
to offer to the user as a possible key in the alist.
For other custom types, this has no effect.