SQL Server functions

If a function returns a table you must grant SELECT permission on it, not EXECUTE.

If a function has a default parameter, caller cannot omit it from the parameter list, but must put the keyword default in its place. (Not terribly useful)

You can't join to a table-valued function, as you can only supply a function with constants or variables as parameters. (You can of course insert its result into a temp table or table variable, and then join to that).