Random considerations

Database storage

Multi-language

Either use different columns (not pretty, but slightly easier to implement) or different rows. Belgian "only" has 3 official languages, so even with a fourth for English (just in case), the columns approach would not take of that many columns

Storing hierarchy

Hierarchy can go pretty deep (book / chapter / section / subsection / article) ... and is subject to change (e.g. new articles can be added in between existing articles, and moved into a new chapter)

API

GET current or specific version HEAD check if version hasn't changed since date X

Export

OASIS LegalDocML aka Akoma Ntoso