Portuguese follows capitalization rules of other Latin languages, namely:
- Only capitalize:
- The first word of a title
- Proper nouns
This comes down to following the officical rules for "book titles" and not for "titles in journals". There are no specific rules for songs. funag.gov.br advises the lower case approach though.
The above guideline replaced in 2023 the former guideline:
- All words are capitalized
- Except connective words (e.g., e, mas, ou, que, se, para, etc...). See for a complet list here.
- Except prepositions (e.g., de, da, do, a, em, com, por, sem, etc...). See for a list here.
Hence the many possible errors one might encounter in the database.
The forum topic that lead to this change : Portuguese capitalization