What does this mean with dselect

[Patrick Colbeck <pat.colbeck@esc.azlan.co.uk>]

Reply-To: 
Hi

Can anyone tell me what messages like this mean when I use dselect with the
apt access method.

Checking system integrity...ok
The following packages have been kept back
  gobjc smail g++ egcc doc-linux-html wxhelp doc-linux-text 
  
Thanks

Pat