Names have helped researchers connect knowledge about those things. Names, however, are not trivial to recognize for humans and machines alike and can get very long when more information is included. This is clear for IUPAC names for chemical structures: while they are machine readable, they are long and not unique either. Short names and codes are abundantly used to overcome this approach, and this includes identifiers. When global and unique they allows us to make data and knowledge findable and interoperabilty. This talk will represent recent finding around the use of identifiers like the European Registry of Materials identifier and nanomaterial InChI (in development) and semantic technologies like Resource Description Framework, Bioschemas, ontologies, and the compact identifier.