Minimum recommended amplification requirements and amplifier matching

I asked this question in another discussion but this one suits better.

If a speaker manufacturer has the following specs; do they mean the recommended power in 8 ohms or 6 ohms?

Specs:
Impedance: 6 ohms
Recommended power: Minimum 50wpc

Thanks @gdhal 

So, if I buy an amp for my 6 ohms speakers with recommended minimum power of 50wpc and if the amp has a power of 50wpc in 4 ohms and 25 wpc in 8 ohms. Am I meeting the "technical" recommendation?

I know what matters is whatever sounds good to us regardless of the specs (as long as you do not know want concert levels in your room) but I am just trying to learn the technical aspect of it.

Thanks!

No, I know what the designer of my speakers think, Alan Shaw. He thinks for my SHL5 and his other speakers, 100wpc is more than enough. He does not say you need to get 100wpc but 100wpc is a good power if you want some reserve power. I agreed with him before now I have experienced it. My 70wpc Naims although play really good with my speakers, when/if I want to go LOUD (rare but I do), the Naims cannot handle (understandably so) it.

This "wanting more power" thing started when my brother brought his 200wpc (8 ohms) Hypex NC400s to my house. The SHL5s showed me that they can go LOUD without any problem as long as you give the power. This romantic/lush sounding speaker turned into a monster with more power.

There is a video on Youtube at a Harbeth dealer in the Netherlands where Alan Shaw tests the 40.1s and I think they receive up to 700 watts at one point!

All I want to do is to be able to have that reserve power when I want to go loud like I did with the NC400. Though, I need to mention, the NC400 is a very good amp but I still prefer the Naims instead for listening longer periods of time. It is more enjoyable to listen to IMO.