An ObjectLogic file can contain namespace declarations that associate namespace URIs with aliases, that can be used to formulate namespace terms in a more concise way.

:- prefix cars="http://www.cars-r-us.tv/".

:- prefix finance="http://www.financeWorld.tv/".

:- prefix xsd="http://www.w3.org/2001/XMLSchema#".

:- default prefix ="http://www.myDomain.tv/private#".

The code above declares four namespaces. It associates three of them with shortcuts (or aliases) and the last is declared as the default-namespace. Each namespace must represent a valid URI according to RFC 2396 and must end with either "#", "/" or ":". This is essential since these characters mark the separator between the namespace and the local part of an identifier. This convention is particularly important when exporting to RDF/OWL or reading from these formats.