From Wikitravel

For most listings (restaurants, bars, hotels, sites), it's helpful to have a phone number for making contact.

In Wikitravel, we format phone numbers as they would be dialled internationally but in a way that shows the part that can be dialled locally. e.g. use the wiki markup:

''+1 514'' 555-1000

for "+1 514 555-1000" where "555-1000" can be dialed locally.

Area codes and other prefixes should be listed in the Contact section of the guide.