6.1.9.15 End Directive
The END label
directive is optional, but if
present should be at the very end of the program. It will terminate the assembly and not
even blank lines should follow this directive.
If an expression is supplied as an argument, that expression will be used to define the entry point of the program. This is stored in a start record in the object file produced by the assembler. Whether this is of any use will depend on the linker.
For example:
END start_label ;defines the entry point
or
END ;do not define entry point