Parsing Ordinals Transaction, the inscribed data part

Question

I am interested in Ordinals transactions' raw hexadecimal format. The example transaction I'm using is TXID: 6fb976ab49dcec017f1e201e84395983204ae1a7c2abf7ced0a85d692e442799. There are some parts of the witness section of this transaction data that I cannot comprehend.

"5503" # 853 bytes
"20" # 32 bytes
"4a3ca2cf35f7902df1215f823d977df1174048b062e03a44f71c2ee736a60cc5" # (A)
"ac" # OP_CHECKSIG
"00" # OP_FALSE 
"63" # OP_IF
"03" # 3 bytes
"6f7264" # "ord"
"0101" # N/A N/A
"09" # 9 bytes
"696d6167652f706e67" # "image/png"
"00" # OP_FALSE
"4d" # OP_PUSHDATA2
"0802" # 520 bytes => maximum value
<skipping the following 520 bytes of image data>
"4d" # OP_PUSHDATA2
"1101" # 273 bytes
<skipping the following 273 bytes of the rest of the image data>
"68" # OP_ENDIF
"21" # 33 bytes
"c04a3ca2cf35f7902df1215f823d977df1174048b062e03a44f71c2ee736a60cc5" # (B)
"00000000" # locktime & end of entire transaction data

Can somebody tell me what (A) and (B) represent?

Answer 1

A is the data required by OP_CHECKSIG B is the final witness component

Neither are part of the inscription, they are parts of the normal transaction in which the inscription is lurking.

Answer 2

A and B are not part of the inscription. A is a pubkey contained in the leaf script which is used to check the signature provided in the first witness item, B is the control block containing the leaf version and internal key. Also see: https://bitcoin.stackexchange.com/a/111396/5406