different sings on effect insert...what there are?

hi

there are few different sings on effect insert could anyone explain to me please…

Marry X-mass

thx
cubase ques3.JPG
cubase ques2.JPG
cubase ques1.JPG

Hi,

Q1: The /// means, this is a VST3 plug-in.
Q2: I’m not totally sure, but I would say the // says, this is a VST2 plug-in.
Q3: Again, I’m not totally sure, but I would say, this is a plug-in, which you can use only once in the project.

Three strikes are vst3, enclosed strikes are 32bit bridged and x are external.