TYPO3 Core

In ext_conf_template.txt the same syntax should be applicable as in the constants editor (according to the core documentation). But labeling a customcategory as described for the constant editor doesn't seem to work anymore in the extension settings since v12.

The "tricks" described in #100936 don't work for me (e.g. adding an empty line afterwards) in the extension settings editor. The labels used for displaying the tabs (i.e. the customcategories) are simply the customcategory name (with ucfirst() applied in v12). This also happens in v13 LTS. In v11 LTS it worked fine.

The labels of customsubcategories are ok.

Example:

# customcategory=api=LLL:EXT:myext/Resources/Private/Language/locallang.xlf:extconf.api
# customsubcategory=baseurl=LLL:EXT:myext/Resources/Private/Language/locallang.xlf:extconf.baseurl

# cat=api/baseurl/a; type=string; label=Files API
filesApi = /api/v1/files/
# cat=api/baseurl/b; type=string; label=Mails API
mailsApi = /api/v1/mails/

The label for customcategory is not shown, but simply "Api" (or "api" in v13LTS), while the label for customsubcategory is shown correctly.