10.9.2 Startup / Group buffer

Question 2.1:

Every time I start Gnus I get a message

            "Gnus auto-save file exists. Do you want to read it?", 
            what does this mean and how to prevent it? 

Question: 2.2		Gnus doesn't remember which groups I'm subscribed to, what's this?
Question 2.3:		How to change the format of the lines in Group buffer?
Question 2.4:		My group buffer becomes a bit crowded, is there a way to sort my groups into categories so I can easier browse through them?
Question 2.5:		How to manually sort the groups in Group buffer? How to sort the groups in a topic?

Question 2.1:

Every time I start Gnus I get a message "Gnus auto-save file exists. Do you want to read it?", what does this mean and how to prevent it?

Answer:

This message means that the last time you used Gnus, it wasn't properly exited and therefor couldn't write its informations to disk (e.g. which messages you read), you are now asked if you want to restore those informations from the auto-save file.

To prevent this message make sure you exit Gnus via `q' in group buffer instead of just killing Emacs.

Question: 2.2

Gnus doesn't remember which groups I'm subscribed to, what's this?

Answer:

You get the message described in the q/a pair above while starting Gnus, right? It's an other symptom for the same problem, so read the answer above.

Question 2.3:

How to change the format of the lines in Group buffer?

Answer:

You've got to tweak the value of the variable gnus-group-line-format. See the manual node "Group Line Specification" for information on how to do this. An example for this (guess from whose .gnus :-)):

(setq gnus-group-line-format "%P%M%S[%5t]%5y : %(%g%)\n")

Question 2.4:

My group buffer becomes a bit crowded, is there a way to sort my groups into categories so I can easier browse through them?

Answer:

Gnus offers the topic mode, it allows you to sort your groups in, well, topics, e.g. all groups dealing with Linux under the topic linux, all dealing with music under the topic music and all dealing with scottish music under the topic scottish which is a subtopic of music.

To enter topic mode, just hit t while in Group buffer. Now you can use `T n' to create a topic at point and `T m' to move a group to a specific topic. For more commands see the manual or the menu. You might want to include the %P specifier at the beginning of your gnus-group-line-format variable to have the groups nicely indented.

Question 2.5:

How to manually sort the groups in Group buffer? How to sort the groups in a topic?

Answer:

Move point over the group you want to move and hit `C-k', now move point to the place where you want the group to be and hit `C-y'.