MedDRA cross-references are inconsistently denoted with MedDRA and MEDDRA.
The following examples include snippets from the HumanDO.obo (revision 2810). Unless otherwise noted, the errors are on the last copied line.
IDC should be ICD for the International Classification of Diseases (last two lines):
def: "A purine-pyrimidine metabolic disorder characterized by deficiency of xanthine oxidase, resulting in excretion of large amounts of xanthine in the urine and the formation of xanthine stones." [url:http\://en.wikipedia.org/wiki/Xanthinuria, url:http\://www.ncbi.nlm.nih.gov/pubmed/4369449]
comment: NT MGI.
synonym: "xanthine dehydrogenase deficiency" EXACT 
synonym: "xanthine oxidase deficiency" EXACT 
IDC should be ICD:
name: mitochondrial complex V (ATP synthase) deficiency nuclear type 3
def: "A mitochondrial metabolism disease that has material basis in mutation in the ATP5E gene on chromosome 20q13." [url:http\://omim.org/entry/614053]
synonym: "MC5DN3" EXACT 
IDC should be ICD:
name: congenital disorder of glycosylation
def: "A carbohydrate metabolic disorder that involves deficient or defective glycosylation of a variety of tissue proteins and/or lipids." [url:http\://en.wikipedia.org/wiki/Congenital_disorder_of_glycosylation]
comment: Xref MGI.
synonym: "carbohydrate-deficient glycoprotein syndrome" EXACT 
UML_CUI should be UMLS_CUI for the Unified Medical Language System:
def: "A tracheal disease characterized by flaccidity of the tracheal support cartilage." [url:http\://en.wikipedia.org/wiki/Tracheomalacia]
synonym: "congenital tracheomalacia" EXACT 
UMLS should be UMLS_CUI for consistency:
name: Cogan-Reese syndrome
def: "A rare eye disease characterized by variable iris atrophy, pigmented and pedunculated nodules located_in iris and attachment of the iris to the cornea (peripheral anterior synechiae) and characterized_by glaucoma." [url:http\://en.wikipedia.org/wiki/Iridocorneal_endothelial_syndrome, url:http\://rarediseases.info.nih.gov/gard/6125/cogan-reese-syndrome/resources/1]