Article categorization is straightforward, by using Evernote Tags.
The following conventions applies for a category tag in Evernote:
As for example for the siteId clbdev there are two categories docker and smallhints attached.
The processed note will look like the following:
As one can see the article is tagged appropriately, as well as there are Categories entries in the right hand menu.
Additionally the Categories menu will have corresponding entries.
There is no limit concerning the amount of categories to be defined.