Where do I put the SFML notice?

[Grime]

1) When do I need to put the SFML notice
https://www.sfml-dev.org/license.php

2) If I made a project based on SFML and posted it on GitHub, do I need to mention the license, where do I mention it? As a text file at the main page? What do I name the text file?

3) Suppose I have not used the SFML DLLs but just copied part of the source code (eg. the part of the library related with clipboard manipulation) do I need to still put the SFML notice?

What happens if somebody didn't put the SFML notice?

[Hapax]

The notice goes with any copies of the source code.

1) It should be left included in all the SFML source code even if you have modified it.

2) If you store any SFML source code on GitHub, the licence should, again, be left included in all of the SFML source code even if you have modified it.

3) Again, the notice is a part of the source code and should not be removed when copied. If you copy only sections, you must still include the notice.

The numbered parts of the notice give a little more detail.

One thing to notice is that if you don't distribute the SFML source code (that includes full copies, partial copies as any manipulated part of the source code), then you don't need to include the licence. That means if you only distribute the DLLs, for example, you don't even necessarily have to mention that you are using SFML.

Basically, the licence is required for the source code but not for any binaries.

What happens if somebody didn't put the SFML notice?

You agree to do so by distributing the source code and would be in breach of the licence.
Note that number 3 clearly states that the "notice may not be removed or altered from any source distribution."