The use case is a Financial message coming from a MASTERCARD switch for instance. See below for an example message (raw):
main ----------> MCBN00000 (SEND) LEN=394 : [ TXN_MCBN_OUT ] [ txn=PURCHASE_EMV_REQ ]< MSG_TYPE,0: 0100 >< P_BITMAP,4: 8538620391460020746 >< DE002_PRIMARY_AC,12: 6737040100000001009 >< DE003_PROCESSING_CODE,33: 000000 >< DE004_TRANS_AMOUNT,39: 000000001999 >< DE006_CARD_BILLING_AMOUNT,51: 000000001999 >< DE007_TRANSMISSION_DATE_TIME,63: 1023084336 >< DE010_CARD_BILLING_CONV_RATE,73: 61000000 >< DE011_SYS_TRACE_AUDIT_NUM,81: 018704 >< DE012_LOCAL_TRANS_TIME,87: 084336 >< DE013_LOCAL_TRANS_DATE,93: 1023 >< DE014_EXPIRATION_DATE,97: 1612 >< DE015_SETTLE_DATE,101: 1023 >< DE016_CONV_DATE,105: 1023 >< DE018_MERCHANT_TYPE,109: 6060 >< DE022_POS_MODE,113: 071 >< DE023_CARD_SEQ_NUM,116: 001 >< DE032_ACQUIRING_INST_ID,119: 000002 >< DE033_FORWARDING_INST_ID,127: 654321 >< DE035_TRACK2_DATA,135: 6737040100000001009D16122010700210600 >< DE037_RETRIEVAL_REF,174: 000000018569 >< DE041_CARD_ACCEPTOR_TERM_ID,186: TEPC0001 >< DE042_CARD_ACCEPTOR_ID_CODE,194: VERSATEST >< DE043_CARD_ACCEPTOR_NAME_LOC,209: Media Markt <> BV>RotterdamZuid>NLD >< DE048_ADDL_DATA_PRIVATE,249: < TCC, 0: R >< SEID23, 1: 01 >< SEID61, 7: 11000 > >< DE049_TRANS_CURRENCY,268: 978 >< DE051_CARD_BILLING_CURRENCY,271: 978 >< DE055_ICC_DATA,274: 5F2A02097882025C00950580800000009A031410239C01009F02060000000019999F10080010A140030000009F1A0205289F260811111111111111119F2701809F360218DF9F37042152D6B1 >< DE061_POS_DATA,353: < LEN_DATA,0: 26 >< DE061_1,1: 0 >< DE061_2,2: 0 >< DE061_3,3: 0 >< DE061_4,4: 0 >< DE061_5,5: 0 >< DE061_6,6: 0 >< DE061_7,7: 0 >< DE061_8,8: 0 >< DE061_9,9: 0 >< DE061_10,10: 0 >< DE061_11,11: 3 >< DE061_12,12: 00 >< DE061_13,14: 528 >< DE061_14,17: 0000000000 > >< DE063_NETWORK_DATA,382: 000018569 ><<<
And formatted:
HEADER main ----------> MCBN00000 (SEND)
LENGTH 394
IDENTIFY TXN_MCBN_OUT
MSG_TYPE 0 0100
P_BITMAP 4 8538620391460020746
DE002_PRIMARY_AC 12 6737040100000001009
DE003_PROCESSING_CODE 33 000000
DE004_TRANS_AMOUNT 39 000000001999
DE006_CARD_BILLING_AMOUNT 51 000000001999
DE007_TRANSMISSION_DATE_TIME 63 1023084336
DE010_CARD_BILLING_CONV_RATE 73 61000000
DE011_SYS_TRACE_AUDIT_NUM 81 018704
DE012_LOCAL_TRANS_TIME 87 084336
DE013_LOCAL_TRANS_DATE 93 1023
DE014_EXPIRATION_DATE 97 1612
DE015_SETTLE_DATE 101 1023
DE016_CONV_DATE 105 1023
DE018_MERCHANT_TYPE 109 6060
DE022_POS_MODE 113 071
DE023_CARD_SEQ_NUM 116 001
DE032_ACQUIRING_INST_ID 119 000002
DE033_FORWARDING_INST_ID 127 654321
DE035_TRACK2_DATA 135 6737040100000001009D16122010700210600
DE037_RETRIEVAL_REF 174 000000018569
DE041_CARD_ACCEPTOR_TERM_ID 186 TEPC0001
DE042_CARD_ACCEPTOR_ID_CODE 194 VERSATEST······
DE043_CARD_ACCEPTOR_NAME_LOC 209 Media·Markt···<>····BV>RotterdamZuid>NLD
DE048_ADDL_DATA_PRIVATE + 249
-TCC 0 R
-SEID23 1 01
-SEID61 7 11000
DE049_TRANS_CURRENCY 268 978
DE051_CARD_BILLING_CURRENCY 271 978
DE055_ICC_DATA 274 5F2A02097882025C00950580800000009A031410239C01009F02060000000019999F10080010A140030000009F1A0205289F260811111111111111119F2701809F360218DF9F37042152D6B1
DE061_POS_DATA + 353
-LEN_DATA 353 26
-DE061_1 354 0
-DE061_2 355 0
-DE061_3 356 0
-DE061_4 357 0
-DE061_5 358 0
-DE061_6 359 0
-DE061_7 360 0
-DE061_8 361 0
-DE061_9 362 0
-DE061_10 363 0
-DE061_11 364 3
-DE061_12 365 00
-DE061_13 367 528
-DE061_14 370 0000000000
DE063_NETWORK_DATA 382 000018569