You need a 'peer-reviewed' journal for a paper to be relevant in your cv in Spain. And by relevant I mean "it DOES count as a paper". If it is not 'peer-reviewed' it does not count.

(Even if they are cr*p, yes).

You may have proved anything. You may even be Thurston. If you do not have 'papers' (like most of Thurston's second era works), they are NOTHING in Spain.

I guess something similar happens in other countries...