Hiya timetofly and thx for your thread. And cool suggestions you have received to. I was never very organized with the subject,but if I were I see merit to the suggestion of color coding for a type but would add numbering the mag to perhaps narrow down a stoppage issue,and even dates of purchase for reference, much less if springs get replace on a schedule. Most of my lower round mags have little or no use,and like the 26rd extended for 9mm shooting.It helps me track,limit the rounds per session. Usually take 250 rds loaded in mags,once empty range visit over. Hope you get organized in a way you are happy with. Be well.