To create a new city press button 
"Create new City" in the City form.
A pop-up form appears.
Fill in the following details:
Name
This is the new city name, for example "London"
AliasName
This is the second city name, for example "London (UK)"
Abbreviation:
This is the abbreviation of the city for example "GBLON" for London
Country:
The related country
(if country is not in the pull-down list, first create country in countries form)
Province:
Related province
(if province is not in the pull-down list, first create province in province form)
District
Related district
(if district is not in the pull-down list, first create district in district form)
Press save.