Meaning of iNTERNAL tag in torrent names

[Nozz]

Have searched and did not find any information in this forum.

Have seen the iNTERNAL tag being used. Example:
Taken.2017.S02E08.iNTERNAL.720p.HEVC.x265-MeGusta

Have also seen the same without the tag. Example:
Taken.2017.S02E08.720p.HEVC.x265-MeGusta

I am confused to which one to choose as in best quality so it would help to learn the meaning of the tag.
Thought at first that the tag meant it were shared in a private group but the torrent with the tag is released long after the one without it.

[Sr_Soil]

Internal is a scene thing. If a group has already released something and another group wants to release the same thing it is then an internal. It is my understanding MeGusta is from IPTorrents so they have nothing to do with the scene so the tag is invalid. 

[contrail]

Not sure how to describe but you can read up about.

https://scenerules.org/

[Sid]

Thought at first that the tag meant it were shared in a private group but the torrent with the tag is released long after the one without it.

Internal means it was created specially for a private group.

But once something has been shared it is almost invariably on-shared sooner or later. Just because it shows up on TPB after a general release doesn't mean it was created after the general release. For reasons of etiquette internal releases are not as freely (i.e. quickly) on-shared as general releases.

And, of course, internals CAN be created for private groups AFTER general releases. They may be different somehow to better fit the norms of the group.

I am confused to which one to choose as in best quality so it would help to learn the meaning of the tag.

That particular tag tells you nothing about the quality one way or the other.