4:59 PM
You said I said " (2) Gyro Gearloose: @MartinSleziak those are lacking proofs and cannot be easily checked (formulas not on one page). What's more, I don't trust wikipedia to be the same tomorrow. Wikipedia is goog enough if I want to look up "John Smith's inequality", but fails when I'm looking for something involving $\ln(1+x^2)$", and really that was my main point.
But if everyone else think this is unnecessary , I won't insist but instead delete my (seen as) stupid proposal. -- I don't feel your comments as "rude", no, definitely not, ..., just discouraging. If my proposal was inappropriate or just misunderstood doesn't make a big difference, so I deleted it.

5:11 PM
@GyroGearloose Well, if we should judge by the only answer which was given there so far, the answer was closer to saying that it is not suitable to this site rather than saying that having such list (elsewhere, if it is not suitable here) would be a bad thing.
And there are some examples of questions on this site which are lists of things or are asking about lists of things.
I have linked to some related discussion on meta in one of my comments; meta.math.stackexchange.com/questions/22475/…
And the question about list of binomial identities which I linked above is somewhat in a similar spirit: math.stackexchange.com/questions/3085/…
In any case, it would be clearer what more users around here think about this if you left the post undeleted. But I definitely won't try to persuade you to undelete it - it is your question, so it's entirely your call.
I can see why you are saying that my comments were discouraging. (Although that was definitely not my intention.)
But perhaps at least this one, which basically says that there are precedents for something similar, can be understood in a positive way:
Jan 24 at 3:55, by Martin Sleziak
(3) Martin Sleziak: To which extent this could be useful is disputable, but I pretty much doubt that creating good list of frequent/useful inequalities would be easy. However, creating lists based on Math.SE questions is not without precedent here. See Catalog of standard exercises and Would “organizer posts” be useful/welcome here?.

5:33 PM
Undeleted it. Just for the fun to see what will happen.

ok
As I said, downvotes on meta do not cost you any reputation.

Reputation is just vanity, aside from the restrictions for having a low budget of "zorkmids". Up/downvotes indicate how a question or answer is received, so I'm inclined to delete the "bad" ones.

5:51 PM
I have tried to formulate what I think about the suggestion a bit more clearly in an answer.
Since you are interested in inequalities, maybe some of the books I mentioned above might be of interest for you: chat.stackexchange.com/transcript/message/27060492#27060492

6:10 PM
I feel you still don't fully get my intention. My intention is not (only) to have access to some heterogeneous list(s) of inequalities (some with, others without proof), but to have here a list of inequalities that can be readily scanned by eyesight&mousewheel, and have proofs attached, separated from the main view by just a single click. (And, hopefully using the same symbols and formalism.)

Well that seems to me rather similar that what was done here with some limits which appear frequently on this site: mathindex.wordpress.com
The difference is that the catalog is not hosted on math.SE. I suppose thats' what you mean by here.
Some lists which are posted on math.SE are linked here. Although in those cases, the posts are not about identities, inequalities and similar stuff.

6:45 PM
Your link is but an external (parasitic?) search engine to what is already here. No all-in-one-page, no link to proofs, ... not at all what I had in mind.

Well, I did my best to say what I have to say on the topic.
Let's hope that other users will post better answers.

7:00 PM
My main point is not to have an answer on the associated question, but to propose a way to avoid (most of) those kind of questions in the future by building some kind of FAQ that could be easily checked.

7:38 PM
Knock Knock

8:12 PM
@GyroGearloose Are you sure we are talking about the same link? That is definitely not a search engine. And every entry there has a link to Math.SE post. They are just divided into pages by topic. For example, Series with radicals. If you click on any formula there, it will get you on the corresponding math.SE page.
So it has links to proofs.

8:34 PM
Although it was generated and not hand-picked, if that's what you meant by "search engine". (But that is definitely not the common meaning of the phrase search engine.)