The TM-CI-Plus ad-hoc working group was launched in November 2011 with the task of providing new CI features beyond the CI+ V1.3 specification, maintained by CI PLus LLP as a publicly available industry standard.
The original Common Interface standard (EN50221) was published in 1997, and extensions to it were specified and published as TS 101 699, in 1999. This work was done under the auspices of the DVB Project. The CI Plus LLP consortium developed the CI+ specification, up to V1.3, which mainly added the feature of a secure return link to the host. Further work on the CI+ specification, starting with V1.4, will be undertaken within the DVB Project.