The original User's Profile directory lives in a directory like C:\Users\username\AppData. How can I refer to the current user's profile directory when using the Windows command line? By searching I found out about %UserProfile% that perhaps refer to the current username, but it does not really work.

The AppData\Local and AppData\Roaming locations are the preferred locations for applications to store data that is not required to be exposed to the user. In a domain environment, the Roaming is used to copy the user's environment as they log on to different computers. You can find a description in the Windows File System Namespace Usage ...

I would just correct that what the OP is asking about are not any special directories or shortcuts but regular environment variables. They may contain any numeric or alphanumeric value, some of them just contain filesystem paths.

Trying to make space on my C drive. I see that my AppData/Local/Packages folder is almost 20GB! Is it safe to delete it? If not, can it be 'pruned' without affecting installed applications?

My AppData\\Local\\Temp occupies 200GB, but cleanmgr.exe says Temporary Files: 1.16MB Why is there the difference? How can I figure out what files in the folder I can delete safely?

I would like to know the full list of variables that I can use in Windows Explorer or related relative paths that is accepted by Windows 10. Variables like %appdata ...

Evidently Microsoft moved away from a Favorites folder used in Internet Explorer that was set to the %UserProfile% with Edge. I have found some information on this on the web i.e. it should be

In AppData however, the user always have rights to write there, even if they are not administrators. So a program that needs to write data, for example a webbrowser with its cache will have to use AppData to write that cache or the user would get an UAC prompt asking for administrative access everytime they start the program.

My guess would be \AppData\Local\Temp, but keep in mind they may not be .txt files. Word for instance when doing autosaves generates .tmp files, so if notepad is using a similar mechanism then it may also be using a similar naming scheme.

If this is the case you might want to use clean-up instead of doing the process manually. Go to Run and type cleanup: Then click Disk Cleanup and choose a drive. Window will pop up where you will be able to select for deletion of temporary (and other mostly useless) files from multiple locations, not just C:\Users\ [Username]\AppData\Local\Temp.