Info_compile_parameters for certain. Documentation also mentiones info_null, info_texlights. There is command "-nomiscents" to leave those unused entities in bsp. For some reason stripping them out on my map caused CS to freeze, but with this command everything is ok. A small test map worked fine either way.
So, after some hustle I've managed to get it working. And it does have impact: previously 3.10 MB map lost weight, and now is 3.07 MB. I went from 862 to 856 entities. I dont' know, this might seem not to be much, but as this map is so close to limits, it's very nice to have some breathing space :). Ok, now I have to do more testing, to see if it did the trick. So far I can say: no visual impact on entities spotted yet :]
I also have contacted FragBait0, authot of opt_entdata. He gave me link to newer, 1.1.2.dev, version. I don't know if I have permission to post the link, or upload it somewhere, so I'll wait for he's reply. This tool is great, I want to share it :].