Document difference between ZIM alias and redirect

[benoit74]

Since I've been for way too long confused about the difference between ZIM alias and redirect, I've created https://wiki.openzim.org/wiki/ZIM_Redirect_Vs_Alias, feedback welcomed if any (feel free to fix the wiki directly)

[rgaudin]

I think what you've documented is what's most important for ZIM creators. It's clear. Fact that is not counted as article (as mentioned in libzim doc seems worth noting).

The fact that we have this page on the wiki would command that we include technical information as well: how is an alias implemented? Just a dirent pointing to another cluster/blob? Same usage of titlePtrPos? What's the advantage of one over the other? It seems that redirect are already lightweight: storing just an int to the dirent entry while alias stores two (cluster and blob).

Thank you for raising this up.

[benoit74]

I agree we should add more, but this is beyond what I'm confident to write 🤣

[rgaudin]

I think @veloman-yunkan would have to do it 😀