After cleaning a bit my raspberry pi I found some packages marked with rc after executing dpkg -l
$dpkg -l [..] ii leafpad ii less rc liba52-0.7.4 rc libaa1:armhf ii libacl1:armhf [..]
What’s that ii and rc mean.
Actually it has not 1 but 3 meaning’s:
First column: Desired
| u | Unknown | 
| i | Install | 
| r | Remove | 
| p | Purge | 
| h | Hold | 
Second column: Status
| n | Not Installed | 
| i | Installed | 
| c | Config-files | 
| u | Unpacked | 
| f | Failed-config | 
| h | Half-installed | 
And there is also a third column: Err? (error?) – If in uppercase, bad errors.
| (none) | |
| h | Hold | 
| r | Reinst-required | 
| x | both-problems | 
So in my case let’s count them:
$dpkg -l | cut -d" " -f1 | sort | uniq -c [..] 662 ii 46 rc
So I have 662 Correctly installed packages (ii) and 46 packages that are remove, but where still config-files for exist(rc).
Now let’s clean the system of this config files (purge): pipe the packagenames into sudo dpkg –purge (with use of xargs).
$dpkg --list | grep "^rc" | cut -d " " -f 3 | xargs sudo dpkg --purge