"WAMMW" is short for "Wenn alle Männer Mädchen wäre" [If all men were girls] and "MESMAAG" is short for "Mit einer Strophe mehr als auf "Geräusch" [With one more verse than on Geräusch].
The acronyms 'WAMMW' and 'MESMAAG' originate from the phrases "Wenn alle Männer Mädchen wäre" [If all men were girls] and "Mit einer Strophe mehr als auf Geräusch" [With one more verse than on Geräusch], which are likely used in a humorous or ironic context.