ISC DHCPv6 clients may use Option Request Option (ORO) defined in RFC3315 [RFC3315] to specify, which options they would like to have configured by DHCPv6 servers. Clients may also be interested in specific options that do not appear in DHCPv6 message directly (top- level options), but rather as nested options or sub-options (i.e. options conveyed within other options). This document clarifies how to use already defined ORO to request sub-options. It also defines new Option Exclude Option (OXO) for cases, when client does not want requested options to appear within specific options. This document updates RFC3315 (if approved).