Yesterday I have seen one of my posts deleted by one moderator with one comment to justify deletion.

I don't deny the justification for deletion (my post was little more than a link to a very good reference URL).

HOWEVER, there was no prior notification or warning, hence I was given no chance to improve my post before deletion.

Since I could still access it, I did perform edits on this answer, but it looks definately deleted, is that correct?

Hence my question: should we accept that our moderators exercize censorship so easily, and without any prior warning?

Shouldn't there be rules of conduct for moderators regarding censorship?

For example, I have seen a few answers with rather rude language being there for long before being edited, and I did not understand why moderators took so long to edit it (I had myself commented to the poster that he should edit his post, which he clearly did not care about).

A problem I see with such beahvior is that, if moderators start getting too keen on easy-going censorship, then I doubt the site will be able to keep its participants for long.

Indeed, it is important to keep in mind that Stack Exchange sites are here for people to help each other, and this is "best effort", some people just don't have enough time to write lengthy answers with all details but feel they can still help with their "simple" answers.

Yesterday I have seen one of my posts deleted by one moderator with one comment to justify deletion.

I don't deny the justification for deletion (my post was little more than a link to a very good reference URL).

HOWEVER, there was no prior notification or warning, hence I was given no chance to improve my post before deletion.

Since I could still access it, I did perform edits on this answer, but it looks definately deleted, is that correct?

Hence my question: should we accept that our moderators exercize censorship so easily, and without any prior warning?

Shouldn't there be rules of conduct for moderators regarding censorship?

For example, I have seen a few answers with rather rude language being there for long before being edited, and I did not understand why moderators took so long to edit it (I had myself commented to the poster that he should edit his post, which he clearly did not care about).

A problem I see with such beahvior is that, if moderators start getting too keen on easy-going censorship, then I doubt the site will be able to keep its participants for long.

Indeed, it is important to keep in mind that Stack Exchange sites are here for people to help each other, and this is "best effort", some people just don't have enough time to write lengthy answers with all details but feel they can still help with their "simple" answers.