Interesting. Not a label I would use. I think whoever put that on is referring to Draco talking a potion to temporarily turn himself female for sex with Harry in A Heart So Ravenous. Since his gender-identity is still firmly male, it's not really a gender switch.

I play with Polyjuice in a number of fics. I think both Harry and Draco use it at various points in the Beauty series (mostly bottom-Harry). Harry gets stuck in the female form in Held in Darkness. I suppose I play with gender in several of my fics.