Many XML applications have recommended prefixes. For example,
SVG elements often use the prefix
svg and Resource
Description Framework (RDF) elements often have the prefix
However, these prefixes are simply conventions, and can be changed based on necessity, convenience or whim.
Before a prefix can be used, it must be bound to a URI.
These URIs are standardized, not the prefixes.
The prefix can change as long as the URI stays the same.