Weird old capacitor values

[qoole]

Hi again,

Whilst rummaging through the old A-Level kit at the school I work at I came across a lovely stash of old electronic components including some caps (I assume they're caps) with rather odd markings.

They're all RS components branded with the following values "100nW" (100 nano farad), "100nZ" (100 nano farad) and "10nW" (10 nano farad).
I have never seen caps with 'W' or 'Z' on them before. Is this some kind of tolerance value.

Attached is a photo of the caps.

Anyone seen anything like this and know what it means?

[Kaluriel]

could be tolerance

[qoole]

I can find 'Z' as a tolerance, but not W...

[Alana]

Encoded max voltage?

[MartinX]

Maybe an indication of the type of dielectric, Z maybe stands for Z5U.

[komet]

Here you go

http://my.execpc.com/~endlr/markings.html

[qoole]

@komet Thanks! That is one VERY useful resource!