Q: List format with --with-colons option

[Bernard]

Hi all

I am writing a basic front end with limited gpg functionality.
My knowledge of gpg is not great and as a start I need some help with
the list format of --list-secret-keys and --list-public-keys.

I found that the --with-colons option returns the most details and
appears to be more machine readable but I don't know what some fields
mean.

Where would I find documentation about this?

I don't know, for example with --list-secret-keys:

sec::1024:17:F27DA7F7725BBB9D:2003-10-23::::myname at actrix.gen.nz
(myname at actrix.gen) <myname at actrix.gen>:::
fpr:::::::::5DDBD04F3450F9E0987211F9F27DA7F7725BBB9D:
ssb::1024:16:C589482C95407314:2003-10-23:::::::


the meaning of 17 in
sec::1024:17
----------^

and how is the key ID extracted from the output? I just guess that
it's the last 8 characters of

sec::1024:17:F27DA7F7725BBB9D:2003-10-23::::myname at actrix.gen.nz
---------------------^

Many thanks

Bernard

My apologies: My ISP uses a white list based SPAM filter so it would
be easier to respond to the list because the filter knows gnupg.org
but does not know individual users of the list who would be blocked.