A few months after becoming unemployed in Geneva I decided to move to Zug (where I had previously lived) in oder to cut costs and take advantage of Zug's much lower tax rate (annual tax is paid in the canton where you are resident on 31 December). Before moving I checked with RAV Geneva, RAV Zug and with my Arbeitslosenkasse Unia if this were possible and all replied to me that yes, it was no problem.
On arriving in Zug I went straight to the local RAV office to register there and was told that I needed my permit to register with them. Of course I had had to give my permit to the Anmeldbüro in Zug in order to register there. It turned out that I had to wait over two weeks to get my new permit from the Zug Anmeldebüro so that was a two week wait before I could register with the RAV Zug. The real problem I had here was the contradictory information I received from Unia and the people working in RAV Zug. Unia insisted I could register with RAV without the permit (which could be provided later). Within the RAV office I heard a different opinion about this from each person I spoke with. I was asked if I had deregistered with the RAV office in Geneva without specifying what deregistering actually meant. I had told RAV Geneva that I was moving but had not signed any deregistration form. RAV Zug refused to contact RAV Geneva to check this. I was also asked, a week after arriving in Zug, to provide them with a copy of my passport and actually told by one person that my passport itself had to be stamped. Similarly, there was a lot of confusion with Unia Zug whether they or Unia Geneva would be responsible for paying me while I waited to register with RAV Zug. Again, each time I contacted Unia on this I got a different answer.
I also had to fill to a new application from with RAV Zug and provide them with much of the same information I had already provided to RAV Geneva, same with Unia.
In the end I got my new permit and was paid at the end of the month but be aware that moving canton as an unemployed foreigner is not so easy and that RAV officials are not always aware of the rules which govern this procedure. In some cantons it can take longer than 2 weeks to get your permit so this may further complicate things with RAV.