The change made escapes equal sign (=) in INFO fields.

However, the column characters : are also escaped on output, as recommended by the vcf 4.3 format.

It is unclear if the column character : should be escaped in INFO fields of vcf files in 4.2 format. The 4.2 format documentation seems to suggest that only whitespace, semicolons, and equals-sign are forbidden (and therefore should be escaped).

In its current incarnation, vcfpy escapes of column characters regardless of the vcf version. It is unclear to me what is the best practical approach for vcfpy, as I am unsure how strictly commonly used software is following the format.