Good luck on this, as it can be a thorny issue at some narrow minded places of employment.

As for me, I neither ask for permission nor simply showed up unanounced.

For a couple of weeks prior to me starting to wear my kilts to work, I made sure to let everyone know I had bought a couple and they were comfortable, explaining about my scottish heritage, etc., etc.

So one day half jokingly and half replying to a dare, I told everyone that I might just show up to work wearing my kilt for casual friday.....so I did.

And then monday kilted...and then tuesday kilted...and everyday until now, it's been what...3 months or so now?

My first Friday kilted I was taken to see the boss, actually...I was taken so the boss can see me, and he really liked the look, asked about every piece of kit and that was that.

I guess you can call it tacit approval.

It 'just happened'