This specification reserves a number of [=properties=] to serve as possible extension points. While some implementers signaled interest in these properties, -their inclusion in this specification was considered to be premature. Some of -these extension points were originally defined in previous versions of this -specification, while others were not. It is important to note that none of these -properties are defined by this specification. Consequently, implementers are -cautioned that use of these properties is considered experimental. +their inclusion in this specification was considered to be premature. It is +important to note that none of these properties are defined by this +specification. Consequently, implementers are cautioned that use of these +properties is considered experimental.
Implementers MAY use these properties, but SHOULD expect them and/or