From Rawpedia:
The wavelet tool is close to being finished (today being 2015-02-11). The information contained herein should be mostly accurate for the wavelet tool as available in version 4.2.217. Some information still needs to be written or updated.
This suggests the information may be a bit out-dated. Is more recent information available?
Its finished and in the last few releases. It has its own dedicated tab.
In upcoming 5.4 release it shares a tab with some other tools.
No problem finding the tool, and it’s good to know it’s finished. However may we expect an updated entry in Rawpedia?
The current entry suggests that there’s more to come:
Some information still needs to be written or updated.
It’s maybe not the good place to ask this question but it’s closely related.
Wavelets tools seem quite extensive, and I have to admit maybe a little bit too much for me 
(I just start using Rawtherapee, 2 years ago from time to time). Lots of adjustment curve, slider,… are available and I feel quite lost in front of them.
So my question is very basic, but I don’t think the answer will be 
. When to use the wavelet tools and how to use them ?
I think I understand how it works (separation of the image in several level of detail layer), but I have no clue how to use it. Any advise ?
Thank you for the link. It’s very usefull 
@patdavid, maybe it could worth to have a link to it in the tutorial section ? or in Rawpedia ?