Website does not allow a count of zero (may be relevant when using the NU code)
Sometimes one will find a used nest with no birds being observed. But the website will not allow for a empty count or a count of 0, so no way to enter a NU code without a count of at least 1. Today I found a used barn swallow nest but no adults (they were present last time I visited but I wasn't able to access the building to find the nest). I had to put a count of 1 but I think in such cases a zero count should be acceptable.