-optional svcpart, required only if the package definition does not contain
-one svc_acct service definition with quantity 1 (it may contain others with
-quantity >1)
+Service to order (see L<FS::part_svc>).
+
+Normally optional; required only to provision a non-svc_acct service, or if the
+package definition does not contain one svc_acct service definition with
+quantity 1 (it may contain others with quantity >1). A svcpart of "none" can
+also be specified to indicate that no initial service should be provisioned.
+
+=back
+
+Fields used when provisioning an svc_acct service:
+
+=over 4