I don't mean to beat this to death, but since I'm familiar with this particular situation I am concerned. If the child's biological father (for lack of a better term) has any common sense at all and is inclined to do just a bit of leg work he can do just that. If he is listed on the birth certificate then all it takes is a trip to the court house, a picture ID and $25 and he has a copy.

Whether or not he's listed on the school's paperwork is neither here nor there. If he shows up at school to get the child and the school calls the police, with that birth certificate (or even without it since the child can say "yes, this is my father") and a lack of legal custody order the police will say "I'm sorry, there is nothing I can do." Then the child remains with him until you "kidnap" him or get a court order stating that you have custody. Without establishing legal custody the schools, daycare, nor the police can help you in this matter.

A friend of ours has been fighting this battle for a long time. His children attend a small private religious school. He enrolled them in this school specifically to prevent his ex-wife from being able to walk into a public school and pull the kids out. I don't know why he felt it was safer, but I digress. She walked out on him and the children five years ago. No one knew where she was or what she was doing. Last year she showed up and took the kids. The school called the police and the father. Once everyone was there, since there was no legal custody order, the police had no choice but to allow the woman to take her children... knowing full well she had Florida plates on her car and was planning on taking them out of state (we're in Wisconsin). The father now had to travel back and forth to Florida in an attempt to get his children back.