Thanks for reporting the issue.
The "Category" names are set by the users when they define their shortcut.
Their is no naming convention associated to these. If one, such as ParticleSystem for instance could be named better, this should be reported as a ux design bug to the team in charge of the particle system.
But once again, Categories are not submitted to any Naming convention, it is defined directly by the path specified for the shortcut in the shortcut attribute.