Hi all,
I've just written a tool adding one or more **extra column** in a [VCF file](http://www.1000genomes.org/wiki/doku.php?id=1000_genomes:analysis:vcf3.3). The header now looks like this:

	(...)
	#CHROM    POS    ID    REF    ALT    QUAL    FILTER    INFO    MY_COL1    MY_COL2    FORMAT    NA00001    NA00002    NA00003
	(...)

Is there something in the **VCF** spec saying that another column can't be added ?
because when I used **VCFTOOLS**, it says:

	vcftools --vcf file.vcf 
	(...)
	Scanning file.vcf ... 
	Ninth Header entry should be FORMAT: MY_COL1
	Currently scanning CHROM: 19
	Currently scanning CHROM: 20
	Currently scanning CHROM: X
<p>BEDTools now supports VCF and you can tack on any number of columns you want.  That said, if you are looking for specific functionality within VCFTools, then this isn't helpful at all.</p>