Best way to link this page

I have moved the page to "OpenFOAM guide" in the new category "OpenFOAM source code documentation". This new category should be sufficiently broad to cover a wide range of (future) pages, but still specific enough as to only attract readers which are actually looking for this information.

Currently, the subpage "lagrangian" is a subpage of a parent page UML, and not linked via a category (as I understand is [http://openfoamwiki.net/index.php/Category:OpenFOAM_guide#Organize_articles_by_category.2C_not_title the convention]?).
I purposely made this a subpage ("OpenFOAM guide/UML/lagrangian"), since a future page "OpenFOAM guide/lagrangian" is not hard to imagine, whilst it will serve a different purpose.
Linking it via a subpage (for the unicity in name) AND a category seems verbose to me.

Also, subpaging + categorizing (as is currently done for all "OpenFOAM guide/..." pages), has the problem that everything is categorized underneath the "O", which takes away a large part of the purpose of categorization.

Opinions?