For laptop who lacks of Caps Lock indicator, it's headache to check the button again and again. So, adapt a plugin should be a good idea. For Debian, I select indicator-keylock who was designed for Ubuntu although. You can find details here . Download .deb file on the right side. Right click to install with GDebi Package Installer, then logout to active it as following: Indicator for Lock Keys: An appindicator for showing the status of the keyboard lock keys, including Caps Lock, Num Lock and Scroll Lock.
Debian, Linux and Python Lover