Note we cope with zero-but-true in order to implement a basic
"exists(something)" check where "something" may even be zero.
Eg in the aux tag searching syntax, "NM" should return true if
NM tag exists even if zero.
Take care when negating this. "NM != 0" will be true when
NM is absent, thus consider "NM && NM != 0".
Note we cope with zero-but-true in order to implement a basic "exists(something)" check where "something" may even be zero.
Eg in the aux tag searching syntax, "NM" should return true if NM tag exists even if zero. Take care when negating this. "NM != 0" will be true when NM is absent, thus consider "NM && NM != 0".