I have Vigor 2860 VAC and found on the web I can prefix a number with #0 and pause to select that my outgoing call will be carried by the POTS (non VOIP phone) line if connected to the router. This does not appear to be covered in the manual or quick start guide. Are there any other pre fix dialling codes to be aware of? If so where can I find them?

For example, can I prefix a call with a code and select which VOIP account carries my call? I know that the phone book may address this and phone book entries are selected by dialing nn* where nn is two digits in the range 00 to 60.

It's actually only #0 that is used as a default (as far as I'm aware), this switches the relay so that the phone is connected directly to the POTS line.

There is the Digit Map facility, which gives you many more options for configuring how calls are routed; this guide is currently specific to the BX2000 PBX, but the VoIP router's Digit Map is all set up in the same way, you just select Accounts/PSTN instead of Trunks: http://www.draytek.co.uk/support/guides/kb-bx2000-digitmap