A classic example of a siman muvhak is a hole by a letter in a get. Only the true owner would be able to know that.
Is the hole visible to the finder (without it being brought to his attention)?
Otherwise, to the finder, it would seem that the get (or any other object with a non-obvious siman muvhak) has no siman, and the finder would not bother to announce it, assuming the owner gave up hope of ever getting it back, when in reality it contains a siman muvhak that the finder is unaware of....
Thanks,
Daniel Steinberg
The story was that somebody found a get which said in it (for the sake of argument) that Kalonymus Steniatzky divorced his wife Tanya. It so happens that the finder knows a couple called Kalonymus and Tanya Steniatzky (who unfortunately have not been getting on so well together, so it is possible that they were going through a divorce), so clearly the finder must return this Get.
The problem is that when he contacts Mr. and Mrs. Steniatzky, there is a dispute between them. Kalonymus claims that he did indeed write this Get but then he decided not to give it to his wife but rather to try again and make the marriage work, and then the get fell out of his pocket. Tanya claims that her husband did give her the Get and it later fell out of her pocket. Since Tanya gives a stronger Siman (a hole by a letter), we give the Get to her even though Kalonymus also gives a Siman, but not such a strong Siman as Tanya's.
Kesivah v'Chasimah Tovah!
Dovid Bloom