I created a Belt Testing Check Sheet for my students. They get a copy in their Recorder Notebook for their own records and goals, but my copy is the one that counts. Here are a couple of sample entries:

WHITE - must achieve this level for passing grade, first nine weeks
Date
_____ Demonstrates proper Ready and Rest positions
_____ Correctly identifies music staff, treble clef, bar line, measure
_____ Correctly identifies and counts half note, quarter note, half rest, 4/4 time signature
_____ Correctly identifies and plays notes G, A, B on staff
_____ Plays "Hot Cross Buns" with no mistakes

YELLOW - must achieve this level for passing grade, second nine weeks
_____ Correctly identifies breath mark
_____ Plays "Gently Sleep" with no mistakes

And so on. Each level requires my signature and date of completion. While the belts have to be earned in succession, they may demonstrate individual skills at their own pace (e.g., I'll give credit for music symbol ID skills even if they can't play the piece yet).