This documentation is not using the current rendering mechanism and is probably outdated. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.
Using htmlArea RTE in a front end plugin¶
If you are a TYPO3 front end extension developer, your extensions may use the htmlArea RTE API to enable rich text editing of text fields. You will find the the htmlArea RTE API Manual on the TYPO3 Extension Repository (extension key: rtehtmlarea_api_manual)
Note that the TYPO3 Image, TYPO3 Link , User Elements and Acronym features are not available when the RTE is used in the TYPO3 front end.