I have found this strange bug in MetaEditor 5.0 Build 883:
Using //text, or /*text */ tags gave the same result.
It is not a bug it is intended behaviour.
From the MetaEditor help file:
It is possible to set another way to display names of input
parameters in the Inputs tab. To do this, a string comment is used, which should
be located after the description of an input parameter in the same line. Thus,
names more understandable for a user can be matched to input parameters.
Also you might want to read this: https://www.mql5.com/en/forum/148851/page7#895276