Mamma is the thirtieth letter of the Gurmukhi painti and closes the labial series, and with it the five by five grid of ordered consonants is finished. It writes an m: the lips close, the voice runs, and the air is released through the nose. Among the five series nasals it is second only to Nanna in frequency, appearing at the beginning, in the middle and at the end of words throughout Punjabi and throughout the language of the Guru Granth Sahib. The five nasals between them show the whole range of what a series slot can mean in practice. Two of them, the velar and the palatal, are barely written; one, the retroflex, is a working letter with a restricted distribution; and two, the dental and this one, are among the most used letters in the alphabet. The grid gives them equal weight and the language does not.
Mamma is also the last letter about which the ordering by place of articulation has anything to say. The five letters that follow it are sonorants and semivowels, sounds made with no closure at all, and they are grouped at the end of the painti because there is no point in the mouth at which to file them. The completion of the grid at Mamma is a real event in learning the script rather than a bookkeeping detail. Up to this point every new letter has been placed by two questions, where the closure is made and how it is released, and a learner who has followed the sequence can predict most of what a letter will be before seeing it. From Yayya onward that method stops working, because the remaining letters are defined by the absence of a closure, and they have to be learned one at a time. Teachers of the painti generally mark the transition explicitly for that reason.