\f
DEFUN ("catch", Fcatch, Scatch, 1, UNEVALLED, 0,
"(catch TAG BODY...): eval BODY allowing nonlocal exits using `throw'.\n\
-TAG is evalled to get the tag to use. Then the BODY is executed.\n\
+TAG is evalled to get the tag to use; it must not be nil.\n\
+\n\
+Then the BODY is executed.\n\
Within BODY, (throw TAG) with same tag exits BODY and exits this `catch'.\n\
If no throw happens, `catch' returns the value of the last BODY form.\n\
If a throw happens, it specifies the value to return from `catch'.")