Check if the DTEP can act as a top level DTEP. This means that the document can be of this type. Some pseudo DTEPs cannot act as a top level DTEP, like PHP as they are always included as part of another DTEP, while some others can be included and act as standalone as well, like the case of CSS.
Marqueu- lo si el DTEP pot actuar com un DTEP de nivell superior. Això vol dir que el document podrà ser d' aquest tipus. Alguns pseudo DTEP no poden actuar com de nivell superior, per exemple PHP, atès que sempre s' inclouen com a part d' un altra DTEP, mentre que d' altres també poden actuar en solitari, com ocorre en el cas de CSS.