The GATK output vcf file contains genotypes in which alleles could be separated both by vertical bar ("|") and slash symbols ("/"). For example: 0/1, 0|1, 0/0, 1|1. I found the explanation at EBI portal. It is said that
The vertical pipe | indicates that the genotype is phased, and is used to indicate which chromosome the alleles are on. If this is a slash / rather than a vertical pipe, it means we don’t know which chromosome they are on.
Does this statement correct for GATK output?