Hi,

The below link suggest that there are three major PCQ groups - but it doesn't really explain what any of them do.
I've tried Googling but I'm not having much luck and I thought that perhaps somebody could shed some light on this for me.

Three Major PCQ Groups:

- Equal bandwidth for a number of users
- Certain bandwidth equal distribution between users
- Unknown bandwidth equal distribution between users.

Link:
https://wiki.mikrotik.com/wiki/Manual:Q ... Q_Examples

Could you please explain a scenario where each of these could be applied and what the differences are?

Thanks!

Have you found the answer? I'm looking at this too.
In PCQ Examples there's a legend saying

Note: More information about certain and unknown Distribution between routers can be found in PCQ manual.

But on the PCQ manual there's no mention to those scenarios

- Certain bandwidth equal distribution between users

ISPs for example, at a given time they could have their links almost free, but they offer different plans(For instance 25$ for 20Mbps, 40$ For 40Mbps, etc.. also could include sharing levels). Therefore, ISPs want to control their traffic by groups. Assigning a certain limit for each group.

- Equal bandwidth for a number of user

Where all the users will get the same amount of bandwidth, It's like the previous example, where only one group exist.

- Unknown bandwidth equal distribution between users.

I can't give you a real scenario, because, in order to Mikrotik work properly, it's suggested to establish the the limit-at and/or max-limit
See: PCQ Rate Examples

Here it is possible to see what happens if PCQ-rate is, or isn't specified. I must noted that if both limits (pcq-rate and max-limit) are unspecified, queue behavior can be imprecise. So it is strongly suggested to have at least one of these options set

I hope this helps you.

Additionally, I think that the terminology used in https://wiki.mikrotik.com/wiki/Manual:Q ... Q_Examples is not formal nor a standard (Maybe I'm wrong).