Given that the topic of the site is Spanish and the language of Stack Exchange is English it seems of course natural to sometimes compare the two languages within a question about Spanish here.
But what about comparisons with other languages? Should we accept it in fairness wherever it's relevant to the question? Allow only related Romance language or languages that contributed etymologically like Arabic, Basque, and Native American languages? Or should we ban any mention of any languages other than just Spanish and English?
It's quite apparent that Stack Exchange has many contributors whose primary language is not English but who use English as a medium of international communication. They may have relevant observations between their language and the Spanish they're learning and still have a number of peers present here, thus making such questions "long tail" rather than "too localized".
On the other hand, some other SE sites such as Japanese Language & Usage often seem to react strongly against any mention of Chinese or Korean for instance.
Obviously, asking questions in any language other than English or Spanish is not acceptable and asking questions not directly about any language other than Spanish is not acceptable. I'm only asking about cases where a question in English or Spanish asking directly about Spanish might makes some parallels or comparisons etc with another language such as Portuguese, French, or German.