Manuel Carro <mcarro@fi.upm.es> writes:

>> Then `tick' the articles, as Steinar suggested in his first mail:
>> `gnus-summary-tick-article-forward' is bound to `u' in summary and
>> article buffer. That'll mark the article with a `!' and it'll show up when
>> you enter the group. It's useful to "bookmark" read articles that still
>> require some action on your part.
>
> This I do (manually) for messages that I have read and I know I will
> have to work on or refer to later on before sending them to their final
> group.  Sorry I did not mention this before.  In short, I'd be glad if I
> could distinguish between the following three categories:
>
> - Not-yet-read messages.
> - Read messages.
> - Read messages which I manually tick as a reminder that they are special.
>
> Cheers,

Three ticked, two read, one old and one unread message, easy to
distinguish: