Make messages easy to find

To make messages easy to find through a where-used search from transaction SE91, use the following pattern:

MESSAGE e001(ad) INTO DATA(message).

In case variable message is not needed, add the pragma ##NEEDED:

MESSAGE e001(ad) INTO DATA(message) ##NEEDED.

Avoid the following:

" anti-pattern
IF 1 = 2. MESSAGE e001(ad). ENDIF.

This is an anti-pattern since:

• It contains unreachable code.
• It tests a condition which can never be true for equality.