>>> "TH" == Tassilo Horn <tsdh@gnu.org> writes:

> Uwe Brauer <oub@mat.ucm.es> writes:
>>> At this point I would suggest using nnselect groups rather than
>>> nnvirtual groups for this sort of thing. I think you'll find they
>>> work much more reliably. See the "select groups" section of the Gnus
>>> manual.
>> 
>> No sure I understand, can I do that interactively on the fly as I can do
>> this with virtual groups?
>> 
>> Do you really mean this
>> http://www.gnus.org/manual/gnus_80.html#Select-Methods

> No, he means (info "(gnus) Selection Groups").


Well, the latter gives me, and I quote 

,----
| 
| 7 Select Methods
| ****************
| 
| A “foreign group” is a group not read by the usual (or default) means.
| It could be, for instance, a group from a different NNTP server, it
| could be a virtual group, or it could be your own personal mail group.
| 
|    A foreign group (or any group, really) is specified by a “name” and a
| “select method”.  To take the latter first, a select method is a list
| where the first element says what back end to use (e.g., ‘nntp’,
| ‘nnspool’, ‘nnml’) and the second element is the “server name”.  There
| may be additional elements in the select method, where the value may
| have special meaning for the back end in question.
| 
|    One could say that a select method defines a “virtual server”—so we
| do just that (*note Server Buffer::).
| ETC ETC 
`----

While  the former via the link 

,----
| A foreign group is a group not read by the usual (or default) means.
| It could be, for instance, a group from a different NNTP server, it
| could be a virtual group, or it could be your own personal mail group.
| 
| A foreign group (or any group, really) is specified by a name and a
| select method. To take the latter first, a select method is a list
| where the first element says what back end to use (e.g., nntp,
| nnspool, nnml) and the second element is the server name. There may be
| additional elements in the select method, where the value may have
| special meaning for the back end in question.
| 
| One could say that a select method defines a virtual server—so we do just that (see section Server Buffer).
| ETC ETC
`----

Call me shortsighted but they look identical to me.