docs-xml: Update documentation for --use-kerberos and --use-krb5-ccache

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>

Autobuild-User(master): Andreas Schneider <asn@cryptomilk.org>
Autobuild-Date(master): Tue Aug  5 11:49:35 UTC 2025 on atb-devel-224

Author: cryptomilk

docs-xml/build/DTD/samba.entities

@@ -764,10 +764,19 @@
 	<term>--use-kerberos=desired|required|off</term>
 	<listitem>
 		<para>
-			 This parameter determines whether Samba client tools
-			 will try to authenticate using Kerberos. For Kerberos
-			 authentication you need to use dns names instead of IP
-			 addresses when connecting to a service.
+			This parameter determines whether Samba client tools
+			will try to authenticate using Kerberos. For Kerberos
+			authentication you should use DNS names instead of IP
+			addresses when connecting to a service.
+
+			By default Samba client tools will try to use the
+			default Kerberos credential cache (ccache).
+			In case the ccache does not exist or -U|--user option
+			was specified, clients will ask to enter a password and
+			will obtain a Kerberos ticket (kinit) for you.
+
+			If you want to use an alternative Kerberos credentical
+			cache, use the --use-krb5-ccache option.
 		</para>
 
 		<para>
@@ -789,7 +798,7 @@
 		</para>
 
 		<para>
-			This will set --use-kerberos=required too.
+			This will enforce --use-kerberos=required.
 		</para>
 	</listitem>
 </varlistentry>