Urtext editions

[megakentar]

I've read that there are much controversy over the  authenticity of the Urtext editions.
Could someone fill me in on this?
I also have a question about all the parenthesis around the accidentals, notes, and etc.
Are these just editor recommendations?

[lorditachijr]

In most cases, urtext editions are reliable. Some are more reliable than others. I don't, however, always recommend urtext. It really depends on the composer, editor and what you prefer personally. The advantage with a lot of urtexts is that you know what the composer wrote and what he/she didn't. As to your question about the parenthetical items, it depends on what is in the parentheses.

If it's an accidental/natural, it's a cautionary accidental. These accidentals/naturals are understood in the music, but the editor judged that they were easy to miss and felt that a little reminder would be helpful.

If fingerings are in parentheses, they usually belong to the editor.

I'm not entirely certain about notes in parentheses, but they may be an Ossia (as in there are two or more different ways to play it that have at least some merit).

Overall, it's probably best to research and ask your teacher which edition is best for whatever piece you are working on.