Action not otherwise provided for

What does Action not otherwise provided for mean in American Law?

The definition of Action not otherwise provided for in the law of the United States, as defined by the lexicographer Arthur Leff in his legal dictionary is:

A phrase commonly appearing in statutes which divide up actions for some purpose (e.g., length of applicable limitations period, courts with initial jurisdiction) to take care of any action which may not have been specifically assigned, as in “all actions not otherwise provided for herein shall be brought within three years …”