I need to remove one level of indentation when coding

I use a variety of text editors such as Geany, N++, gedit, and Code::Blocks

Notepad++

Select the lines you want to "unindent" and press shift+tab

Geany

Select the lines you want to "unindent" and press shift+tab or ctrl+u

gedit

Select the lines you want to "unindent" and press shift+tab

Codeblocks

Select the lines you want to "unindent" and press shift+tab