Is the supplication of qunut in the witr prayer prescribed throughout the year, and is it performed before or after the bowing, and is it permissible to add to the narrated supplication?

The questioner : You once told me that the qunut in the witr prayer is [performed] throughout the year.

The Shaykh : Throughout the year, but not always.

The questioner : Yes.

The Shaykh : Sometimes and sometimes.

The questioner : Sometimes and sometimes, that is correct.

The Shaykh : And when I told you "throughout the year," the answer was that it is not in the second half of Ramadan.

The questioner : Yes, that is right.

The Shaykh : That is the intention, but the intention is not that it is in every witr, is it?

The questioner : I mean, if one chooses one day like this and another day like that.

The Shaykh : Yes, exactly.

The questioner : So, is it permissible for us to make this qunut supplication, because what is reported in the Sunnah is before the bowing, so if we do it after the bowing, it becomes...

The Shaykh : It becomes following 'Umar and others like him, but the Sunnah is more beloved to us.

The questioner : Yes, the one before the bowing is better.

The Shaykh : Yes, exactly.

The questioner : So, if we add a supplication to this narrated one, is it permissible? I mean, the well-known one, and so on, do I add other supplications from myself?

The Shaykh : No, it is not permissible except rarely.

The questioner : Except rarely.

The Shaykh : Yes, exactly.