What these strange TXT records in my default OVH DNS config mean
Based on this post at OVH community forums in French, it seems to be automatically added when domain is created in order to display the default webpage.
Rough translation of the French message:
These records are used to display the web page "Félicitation votre domaine vient d'être créé chez OVH" ["Congratulations your domain name has just been registered with OVH"] (txt - welcome) in French (TXT - fr)
In your case it will be in Portuguese pt
as the original question on the French forums was for:
www IN TXT "3|welcome"
www IN TXT "l|fr"