Modules namespace, slash vs hash

[anaigmo]

Regarding the decision of which namespace should we use for the RML ontologies (core + modules), there are three options, and they also influence the use of hash or slash:

1. All modules with same namespace: All concepts share the same namespace, they are divided in different files and published independently from different repositories. Hash/slash indifferent.
2. Different namespace per module: Each module has a different namespace, including all the concepts they define. Also divided in different files, published independently, and indifferent hash/slash. Easier to manage each module, more difficult to remember to which module each term belongs. Example with hash and with slash.
3. Hybrid: Same namespace for all terms, but each module has a different IRI. The terms have a rdf:isDefinedBy property that points to the module IRI. Harder to publish with hash, it would require publishing with slash. Example.

[bjdmeest]

I am pro making the user only remember one prefix as much as possible, but also make each modules accessible independently, so option 3 feels most future-proof (modules can be versioned independently and also still used separately in different contexts).
I think slash vs hash still is open, e.g. https://docs.enslaved.org/ontology/ also combine independent modules for each version, using hashes (and I assume that's the same for SHACL extensions: https://www.w3.org/TR/shacl-af/#SPARQLTarget). However, https://www.w3.org/wiki/HashVsSlash favorites slash, so I'm fine to use that as a reason to pick one or the other

[pmaria]

Agreed.

Note that with option 3, using a single namespace, IRI dereferencing of the ontology(s) using a hash strategy does not afford the ability to distinguish modules. With hash you could only ever serve a single document per namespace.

[anaigmo]

As agreed on the Community Group's meeting, we propose to go for option 3 (hybrid) to maintain the same namespace for all concepts but keeping differenciated the modules; and with slash, since with hash it would not be possible to split the modules in different files.

If you agree please let us know reacting to this message with 👍 ; else with 👎 -- and explain further why not in a comment below :)

[DylanVanAssche]

We have an agreement around slash vs hash for all ontologies. Closing.