commonscat has a dict ignoreTemplates with some entries as tuples like:

ignoreTemplates = {
...
    'eo': [u'Commons',
           (u'Projekto/box', 'commons='),
           (u'Projekto', 'commons='),
           (u'Projektoj', 'commons='),
           (u'Projektoj', 'commonscat=')],
...

The method skipPage is supposed to ignore the page if the template exists with the mentioned parameter name.
However the logic only compares the first parameter of the template in the page against that the mentioned parameter name.
The commonscat logic for this dates back to 2008 (901e48d39).