Female -> female love & female + female relationships.
Should be mostly explanatory when reading the chapter/series.
Does NOT matter what the setting is, just needs to feature love involving two women (including transgender women).
For stories with extra ambiguity, consider the Subtext tag instead. For stories featuring one-sided love as a side-plot or secondary character trait, use Yuri crush.

Should NOT be paired with the futanari tag unless there is somehow a separate relationship that does not involve futanari.