Proportion of low quality reads
INFO=<ID=LowMQ,Number=3,Type=Float,Description="3-tuple: <fraction of reads with MQ=0>
This annotation tells you what fraction of reads have a mapping quality of less than the given threshold of 10 (including 0). Note that certain tools may impose a different minimum mapping quality threshold. For example, HaplotypeCaller excludes reads with MAPQ<20.