This is OCL (Object Constraint Language) simple syntax highlighting for Notepad++.
Works with .ocl and .OCL extensions.
Replace your userDefineLang.xml located in %USERPROFILE%\AppData\Roaming\Notepad++ with the
userDefineLang.xml file in this repository.
If you already have other custom language highlighting you should copy the content of the file between
<UserLang name="OCL" ext="ocl OCL" udlVersion="2.1"> and </UserLang> (including these lines) and paste
into your userDefineLang.xml file.