symbol-package

(symbol-package symbol)

Lite: returns the same keyword shape find-package returns, so the two are eq-comparable: :keyword for a keyword, the qualifier of a package-qualified symbol, :cl for a standard symbol (t, nil and the exported-only standard names included), :cl-user otherwise, and nil for an uninterned (#:) symbol -- or for one unintern removed from its home package. The compiled backends read the home off the symbol's spelling, telling a standard symbol from a cl-user one by a table of the standard names the program then carries; they keep the home of a symbol unintern removed.