Appendix 1 is a listing of all sources within the current version of the Metathesaurus with an indication of any additional restrictions and notices that apply. Sources are listed in order according to the abbreviations used in the UMLS Metathesaurus files. All sources are subject to the general terms of the License for Use of the UMLS ® Metathesaurus ® . The Categories associated with each source are defined in the general license as follows:

CATEGORY 0 RESTRICTIONS – General terms of the License apply with no additional restrictions

CATEGORY 1 RESTRICTIONS APPLY

CATEGORY 2 RESTRICTIONS APPLY

CATEGORY 3 RESTRICTIONS APPLY

CATEGORY 4 RESTRICTIONS APPLY