Table 1.

Class definition of virtual genomic SAGE tags

TAG CLASS
ID	NAME	DESCRIPTION
Pt	Platinum	TAG is unique in the genome and it matches a transcript
Au	Gold	TAG is not unique in the genome and it matches a transcript, but other occurrences of this TAG always match intergenic regions
Ag	Silver	TAG is unique in the genome but it matches two or more overlapping transcripts located at the same genomic region
Al	Aluminum	TAG is not unique in the genome, it matches a transcript, but other occurrences of this TAG also match another transcript located at a different genomic region
Cu	Copper	TAG is unique in the genome and it matches an intergenic region
Fe	Iron	TAG is not unique in the genome, it matches an intergenic region, but other occurrences of this TAG always match an intergenic region
Si	Silicon	TAG is not unique in the genome, it matches an intergenic region, but other occurrences of this TAG match a transcript