many of us associate the word mark with grades received in school. This is precisely what the title of this poem is refering to. This idea of marks as grades is illustrated with the speakers family members. Each family member has their own grading system to evaluate the speaker. The husband uses a letter grading system, the son a ranking system, and the daughter simply grades her mother on a pass/fail system. As you can see, there is extensive textual evidence to support this metaphor.