Man-Related refers to genders that are related to, but not aligned with, being a man. Man-related individuals are not man-aligned at all, but feel as though they're in the same or a similar "category" as men. It is similar to how purple and green are different colors, but they’re both still considered “cool colors” and are in the same category, or how hyenas and cats are extremely different animals, but are both a part of the same suborder. It is something completely separate, but connected in some way.
Man-related and masc-related are not the same term, as being a man and being masculine are not synonymous.
Some identities that may fall under man-related include:
The man-related flag was made by Tumblr user quiet-times on November 1, 2020. The stripes have no written meaning, but are presumably to represent colors that are similar, but different, to traditionally masculine colors, like blue.