leupold wrote
language changes don't get overwritten, if you use language in admin menu or language in host menu and select host mode in language editor. However, if keys are moved, you need to add the texts for the new key locations again.
This I didn't know: if you use... Host > Languages > Language Editor > Mode: HOST - the language changes made will persist across all portals for an installation, and NOT be overwritten by upgrades. That's good to know; thanks for pointing that out, Sebastian.
For those like you and me who like to tweak language, it would be adventageous if we could better identify where specific language is coming from. This would not work for email/notification language, but for screen language, it would be good if browser/source could help tell where language is coming from. Would it be possible, for example, to have DNN insert a small, 'token key' identifier comment right before a snippet of language that is modifiable in Language Editor? Or maybe the token key 'id' that is viewable in browser > view > source could be better organized by name, associated with the Language Editor folders and individual key names?
While using DNN, I often (1) identify the language text to change, (2) browser View Source, to better identify the key name, (3) poke around Language Editor looking for the key. Sometimes I jump to file system, and Text Search .../Admin and below for all occurances of the text.
Do you see a way to improve this process? Often I change keys I'm not sure I need to change. I spent way too much time looking for the source of text that DNN renders onscreen or in notification emails.
For example, in DNN English, when clicking Login, 'User Log In' displays as the login screen title. Say I want to change this text to 'Client Login' (changing User to Client, and standardizing Log In to Login)
When I text search 'User Log In' from the file system .../Admin down, Login.ascx.resx and Signin.ascx.resx are found to contain that language. Each of these files has three key occurances of 'User Log In'.
So, which of these keys is actually the text I am seeing on the Login screen?
I change all six keys, even if I don't know which one of these is the text on the Login screen Title. Later I find another part of DNN is displaying 'Client Login' where I would rather 'User Log In' is displayed (well, maybe not; because all 'Log In' should be changed to 'Login' at least) 
How can we better know that the language we modify in Language Editor is the language we are seeing onscreen?