NFD » NDN Specifications

One concern of treating "no Parameters" and "zero-length Parameters" as equivalent is: under current protocol, ParametersSha256DigestComponent is required if Parameters are present, and is forbidden if Parameters are omitted.
This leads to a conflict: if an Interest arrives at a node with "zero-length Parameters" and ParametersSha256DigestComponent, and the node decides to re-encode the Interest (e.g. during ForwardingHint modification) with "no Parameters", the node would have to strip away ParametersSha256DigestComponent. Consequently, the new Interest is semantically different from the old Interest because its Name has changed.
Suggested solution: forbid zero-length Parameters outright, so that ParametersSha256DigestComponent can appear only if the Interest has a non-empty Parameters.