jg vs jgl
No difference: both shorten jungle, or jungler. It is a matter of habit, and even players who write one read the other without thinking.
jg
"jg" is the shortest form, two letters, the most common on european servers. It works for the role as for the area: "who jg", "jg diff", "invade their jg".
open the page →jgl
"jgl" keeps one more letter and reads slightly more easily. It comes from the same word, serves the same uses, and coexists with "jg" in the same game: "jgl top side", "ty jgl".
open the page →Why they get mixed up
People think they differ because dictionaries list them separately, or because one player corrects another. There is nothing to correct. The only real mistake is writing "jungle" in full when there is a warning to give: three extra letters is one extra second.
"jg" and "jgl" share a single dictionary page, since they mean the same thing. jgl