Rule 1417 The genuineness of handwriting, or the lack thereof, may be proved by a comparison made by the trier of fact with handwriting (a) which the court find…

When someone questions whether a piece of handwriting is real or fake, a judge or jury can compare it to other handwriting samples to figure out the truth.

The comparison sample must either be writing that the other side has already accepted as genuine, or writing that the court has decided is authentic based on other proof. This gives the person deciding the case a real basis for comparison instead of just guessing.