The above flagholder uses the initial I.A.F.F. organized Feb. 28, 1918.  At the bottom it says AFL-CIO and CLC. This is apparently a labor union affiliated with the AFL-CIO. This is a marker for a member of the International Association of Fire Fighters.

(Note form a guest) Another Mystery Marker you have listed, IAF, 'is' International Association of Fire Fighters http://www.iaff.org/iaff/index.html. Their symbol, listed on the above link, shows the same (even the organized date) symbol.  And as you can see by the url they have IAFF and have Fire Fighters as two separate words. As you noted it appeared to be of Fire Fighter origin the give-away was the maltese cross of the Fire Departments.