Without having more information - the first thing that comes to mind is the size of the nib. (Medium)
Alvin M. Fountain died in 1989.
Alvin M. Fountain was born in 1899.
it is just a letter that can sound like mmmmm or M or m like any other letter
The fountain of Fountain Hills, Arizona,got is name necause it spews water to a height of 562 feet (171 m)
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern --M--PEN. That is, eight letter words with 3rd letter M and 6th letter P and 7th letter E and 8th letter N. In alphabetical order, they are: semiopen
The letter M is equivalent to the number 1000 in Roman Numerals.
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern PEN--M-. That is, seven letter words with 1st letter P and 2nd letter E and 3rd letter N and 6th letter M. In alphabetical order, they are: penname pensums
You are going to get married
There is no m on the indicator
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern PEN--M-N. That is, eight letter words with 1st letter P and 2nd letter E and 3rd letter N and 6th letter M and 8th letter N. In alphabetical order, they are: penwoman penwomen
Mucho
magnificent