Suggestion to use .ifczip extension rather than .zip

[jmirtsch]

I suggest if compressed/zipped example files are added to the repository, they should use a .ifczip file extension rather than .zip
There are a couple such as https://github.com/buildingSMART/IFC4.x-IF/blob/a89e01e4c14c90e7ce77842cabb04b367d437035/IFC-files/IFCRoad-ItalyWG/buildingSMART%20Italy_IFCRoad%20WG.zip

A .ifczip file is typically a compressed file containing only a single step physical file (.ifc)

I think it would be great to encourage greater use of .ifczip extension as a more efficient storage size of infrastructure data sets.

[aothms]

There's also some additional requirements for calling it an official ifczip https://standards.buildingsmart.org/documents/Implementation/IFC_Implementation_Agreements/CV-2x3-154.html This might be horribly outdated (and reduce compression ratios if we disallow deflate64 or other novel algos) but until we retract this statement, we should follow it.

[thbeu]

FYI: For FMI the Modelica Association (where I am member of) came up with the following simple requirements on the ZIP archive:

https://github.com/modelica/fmi-standard/blob/33b7a8c0ee32869bf5ae08d8f435f6ee36939549/docs/2_5_fmu_distribution.adoc?plain=1#L14-L19

This can be easily adopted for ifcZIP by stating that only one file and no directory entries are allowed inside the archive.