Application ID rules are kinda incorrect
Docs say that Application ID is used for DBus and Flatpak, amongst others. However, the "precise rules" allow using hyphens, which are not always allowed for DBus and Flatpak.
From DBus specification:
The hyphen ('-') character is allowed in bus names but not in interface names. It is also problematic or not allowed in various specifications and APIs that refer to D-Bus, such as Flatpak application IDs, the DBusActivatable interface in the Desktop Entry Specification, and the convention that an application's "main" interface and object path resemble its bus name. To avoid situations that require special-case handling, it is recommended that new D-Bus names consistently replace hyphens with underscores.
flatpak build-init gives following error:
error: 'org.gnome.gitlab.delight-aug.Demo.Devel' is not a valid application name: Only last name segment can contain -