Firestore id naming convention [duplicate]

Question

Is there any naming convention for document id in FireStore. I created some documents inside a collection with the date in "yyyy-mm-dd" as the id. When i try to get all documents inside the collection i got the snapshot size as zero. When I put a dummy doc with test as id I got only the test doc not the other docs.

My document structure

Answer 1

The contraints can be seen here Quotas and Limits if you scroll down to the bottom you will find contraints on ids, paths and field names.