Orientation bias in Mutect2 variant calling

Question

[nicola.calonaci]

Hi,

I do not understand properly the meaning of 'orientation bias' in Mutect2 filter values when performing variant calling.

I have read this post on the GATK blog and this issue on the GATK github but did not really understand the difference with respect to 'strand bias'.

Can anyone explain the meaning of this kind of bias in detail?

Many thanks