Convention for the symbol of Dielectric Constant

[Plant_Boy]

I have come across the dielectric constant represented by two variants of epsilon. Is there any convention behind the two variants such that:
\varepsilon is the SI Dielectric Constant
\epsilon is the CGS Dielectric Constant
or does it really depend on the writer and how frisky they feel?

 

[ShayanJ]

There is no famous convention but people can use such a thing as long as they state what they mean by each explicitly. So if nothing is said about such a convention being used, then there is nothing behind it.(Of course assuming a reasonable author!)

 

[Plant_Boy]

Maybe I could start a new convention! XD