rotate uv coordinates / uv of a face

Hello

Cannot remember the keys for rotating the uv texture on a face for 90 degrees,
so what was it ?

thanks

Ctrl + f …

There is a rotate 90 degrees button for the texture itself that you can use.

But you could always simply open up a UV image editor, select the verticies that define the UV area and then press the R-Key to rotate them any amount. Use CTRL-Key to constrain to 5 unit intervals.