I have noticed that in the list of suggested synonyms there is a suggestion to synonymize fractions and rational-numbers. See also here.
I am not sure this is a good idea. For example, I can imagine question tagged as limit+fraction (if it is a question about a limit of the type $f(x)/g(x)$), but if the same question would be automatically retagged to limit+rational-numbers, it would look strange to me.
I would like to know the opinion of other MSE users whether they consider this tag synonym to be reasonable.
I did not find some older discussion about this on meta, but I found this discussion in chat.