> ommon.css requires a class name in each wiki. In order to hide this we need CSS designation for each wiki. I do not understand this part. Or, we do not need to edit common.css (etc).
I'm not 100% sure on the context here, but if we are referring to Recommendations_for_mobile_friendly_articles_on_Wikimedia_wikis#Use_standardized_class_names_in_HTML_markup_for_components_in_templates_across_projects the word "common" here is more to do with using a "standardized" class name (not common.css). One challenge we have with standardising displays across wiki is the class attribute usage in HTML markup.
In Chinese/Japanese might be
To avoid having to localise class names, we're attempting to standardise on a single class across all the wikis.
So in the above case if m-elephant is the "standard", the markup for Japanese/Chinese might become:
<div class="m-elephant m-大象"></div>