In safety data sheets, the identified uses and uses advised against are specified in Section 1. Use descriptions are also used for substances safety reports. If a corresponding substances safety report is available for a safety data sheet, the information in both documents must match. The use descriptor system (UDS) is a categorisation system by ECHA to uniformly classify the uses of hazardous substances through specified use descriptors. The use descriptors are maintained by the ECHA and are published in the Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.12: Use description. There is also a German version of the guideline (Leitlinien zu Informationsanforderungen und Stoffsicherheitsbeurteilung, Kapitel R.12: Verwendungsbeschreibung).