Is there any limitation on the name of the properties of contacts?



sometime when calling the add contact endpoint with some custom properties some field are ignored.
So the question is, is there a limitation on the names like, for example, name containing _ or ? or . $?
for example a property with the following name is ok?



Hi @pie,

Property names must contain only lowercase letters, numbers, and underscores, and they must start with a letter. If you attempt to create a property with an invalid name, you’ll see the above in the resulting error message.