Identify decoupling capacitors?

I'm trying to identify some decoupling capacitors, probably ceramic.
They're orangish red, about 8 x 6 x 1mm axial leaded.
They are labelled on the top, that is the 8 x 1mm curved face
away from the leads:-

104
YME

To the left of this is what I take to be the trade mark which
is a narrow slanted V which is as large as the two lines of
lettering above.
The left arm of the V is about 5 degrees clockwise from vertical
while the right arm is about 10 degrees so the whole V points
down to the left.


I assume 104 means 100nF as it usually does. What does YME
mean?

I'm asking because these caps were provided for a fairly exacting
operation, namely decoupling photomultiplier dynodes in cryogenic
conditions. They'll be run at about 200V and , er, -190C.
They look awfully small for 100nF/300V and I have my suspicions
about their temperature coefficients.
.