Subclauses 9.2 and 9.3 present the NGAP message and IE definitions in tabular format. The corresponding ASN.1 definition is presented in subclause 9.4. In case there is contradiction between the tabular format and the ASN.1 definition, the ASN.1 shall take precedence, except for the definition of conditions for the presence of conditional IEs, where the tabular format shall take precedence. The messages have been defined in accordance to the guidelines specified in TR 25.921. When specifying IEs which are to be represented by bitstrings, if not otherwise specifically stated in the semantics description of the concerned IE or elsewhere, the following principle applies with regards to the ordering of bits:

• The first bit (leftmost bit) contains the most significant bit (MSB);
• The last bit (rightmost bit) contains the least significant bit (LSB);
• When importing bitstrings from other specifications, the first bit of the bitstring contains the first bit of the concerned information;