There is no explicit versioning mechanism for extensions. Nonetheless, there may
be cases in which a developer decides to update an extension after the extension has
been released and client support for the extension has been established. In these
cases, it is recommended that a new extension be created. The extension may have a
name that signifies its relationship to the previous version. For example, a
developer may append an integer to the extension name to signify that one extension
updates another: RAX-PIE2
updates RAX-PIE
.
Extensions may have dependencies on other extensions. For example,
RAX-PIE2
may depend on RAX-PIE
and may simply add
additional capabilities to it. In general, dependencies of this kind are discouraged
and implementers should strive to keep extensions independent. That said, extension
dependencies allow for the possibility of providing updates to existing extensions
even if the original extension is under the control of a different vendor. This is
particularly useful in cases where an existing extension has good client support.