This porn video tag contains four parts:
1. "black" refers to the ethnicity or skin color preference of the performers involved in the scene.
2. "dl" stands for "daddy/little girl" roleplay, which is a type of age play where an older, dominant male takes on the role of a doting "daddy" figure, and his partner takes on the role of a younger, submissive "little girl."
3. "shemale" refers to the presence of a performer with both male and female physical characteristics (often referred to as a transgender or TS performer).
So, this tag is describing a porn video that features an interracial scene involving age play between a shemale/transgender performer and another performer who takes on the role of a submissive "little girl." The other performer may be black, but it's not specified in the tag.