Opcodes

An opcode is one byte of a script that tells the machine what to do: push some data, add two numbers, check a signature. A script is a row of them.

Every byte value from 0 to 255 means something, even if that something is “fail”. This page lists them all as Pearl’s engine treats them. The table is generated from this site’s opcode library, which mirrors Pearl’s opcode.go at v1.5.2.

Try it

Write a script with any of the opcodes below and step through it.

How do the 256 bytes break down?

Push data or numbers

96

0x00–0x60, except 0x50 (OP_RESERVED)

Work everywhere

57

stack, flow, arithmetic, hashing, locks

Tapscript only

5

CHECKSIG, CHECKSIGVERIFY, CHECKSIGADD, CAT, CHECKXMSSSIG

Disabled

16

invalid even in a branch that never runs

Fail when run

82

reserved, NOP slots, unassigned bytes

OP_SUCCESS

0

Bitcoin tapscript has dozens

Since every spendable Pearl output is Taproot or P2MR, every script that runs is a tapscript leaf. So in practice “tapscript only” just means “works”.

Which opcodes are special on Pearl?

• OP_CAT (7e) works. It joins the top two items. Following BIP-347, the result may be at most 520 bytes. Pearl also charges ⌈length ÷ 64⌉ from the signature budget for it. In Bitcoin it has been disabled since 2010, and in Bitcoin’s tapscript 7e is an OP_SUCCESS.
• OP_CHECKXMSSSIG (de) is new. It checks a post-quantum XMSS signature split into five 468-byte items, and costs 1,000 from the budget. Its own page.
• OP_CHECKSIG (ac), OP_CHECKSIGVERIFY (ad), OP_CHECKSIGADD (ba) check 64- or 65-byte Schnorr signatures against 32-byte keys, in tapscript only. An empty signature pushes false; a wrong non-empty signature fails the script. A non-empty key of any other length fails too, where Bitcoin’s tapscript treats it as an unknown key type and lets the check pass.
• OP_CHECKMULTISIG (ae, af) always fails. Use OP_CHECKSIGADD for multisig, as the real 2-of-2 on the Script page does.
• OP_NOP1, OP_NOP4–OP_NOP10 (b0, b3–b9) fail with “reserved for soft-fork upgrades”. In Bitcoin they do nothing.
• Unassigned bytes (bb–dd, df–f9, fc) fail when executed. In Bitcoin’s tapscript each is an OP_SUCCESS that makes the whole script valid.
• OP_CHECKLOCKTIMEVERIFY (b1) and OP_CHECKSEQUENCEVERIFY (b2) work as in BIP-65 and BIP-112, from block 1.

What do the probes show?

These one-line scripts were run as P2MR leaves through Pearl’s own consensus engine:

How does Script write numbers?

Arithmetic opcodes read stack items as script numbers: little-endian, as short as possible, with the top bit of the last byte as the sign. Zero is the empty item.

The last row is a real one: it’s how block 130,825’s coinbase states its height. Tapscript insists on the shortest push, so 51 is the only valid way to push 1.

What limits apply?

• The signature budget. Each input gets 50 plus the size of its witness in bytes. A signature check costs 50, OP_CHECKXMSSSIG 1,000, and OP_CAT ⌈length ÷ 64⌉. Pearl has no other sigops limit: none per block, none per transaction.
• Stack items are at most 520 bytes, and at most 1,000 items may be on the stack.
• Pushes must be minimal: a value that fits in OP_1–OP_16 must use them, and a 5-byte item uses 05, not OP_PUSHDATA1 05.
• OP_IF / OP_NOTIF accept only an empty item or exactly 01 as their condition.
• No opcode-count limit and no 10,000-byte script limit inside tapscript, as in BIP-342.

The full table

Every named opcode. The push range and the unassigned bytes are summarized in the last rows; the complete 256-row table is below it.

All 256 byte values

Byte	Name	On Pearl	What it does
00	OP_0	Push	Pushes an empty byte array (read as 0 / false).
01	OP_DATA_1	Push	Pushes the next 1 byte onto the stack.
02	OP_DATA_2	Push	Pushes the next 2 bytes onto the stack.
03	OP_DATA_3	Push	Pushes the next 3 bytes onto the stack.
04	OP_DATA_4	Push	Pushes the next 4 bytes onto the stack.
05	OP_DATA_5	Push	Pushes the next 5 bytes onto the stack.
06	OP_DATA_6	Push	Pushes the next 6 bytes onto the stack.
07	OP_DATA_7	Push	Pushes the next 7 bytes onto the stack.
08	OP_DATA_8	Push	Pushes the next 8 bytes onto the stack.
09	OP_DATA_9	Push	Pushes the next 9 bytes onto the stack.
0a	OP_DATA_10	Push	Pushes the next 10 bytes onto the stack.
0b	OP_DATA_11	Push	Pushes the next 11 bytes onto the stack.
0c	OP_DATA_12	Push	Pushes the next 12 bytes onto the stack.
0d	OP_DATA_13	Push	Pushes the next 13 bytes onto the stack.
0e	OP_DATA_14	Push	Pushes the next 14 bytes onto the stack.
0f	OP_DATA_15	Push	Pushes the next 15 bytes onto the stack.
10	OP_DATA_16	Push	Pushes the next 16 bytes onto the stack.
11	OP_DATA_17	Push	Pushes the next 17 bytes onto the stack.
12	OP_DATA_18	Push	Pushes the next 18 bytes onto the stack.
13	OP_DATA_19	Push	Pushes the next 19 bytes onto the stack.
14	OP_DATA_20	Push	Pushes the next 20 bytes onto the stack.
15	OP_DATA_21	Push	Pushes the next 21 bytes onto the stack.
16	OP_DATA_22	Push	Pushes the next 22 bytes onto the stack.
17	OP_DATA_23	Push	Pushes the next 23 bytes onto the stack.
18	OP_DATA_24	Push	Pushes the next 24 bytes onto the stack.
19	OP_DATA_25	Push	Pushes the next 25 bytes onto the stack.
1a	OP_DATA_26	Push	Pushes the next 26 bytes onto the stack.
1b	OP_DATA_27	Push	Pushes the next 27 bytes onto the stack.
1c	OP_DATA_28	Push	Pushes the next 28 bytes onto the stack.
1d	OP_DATA_29	Push	Pushes the next 29 bytes onto the stack.
1e	OP_DATA_30	Push	Pushes the next 30 bytes onto the stack.
1f	OP_DATA_31	Push	Pushes the next 31 bytes onto the stack.
20	OP_DATA_32	Push	Pushes the next 32 bytes onto the stack.
21	OP_DATA_33	Push	Pushes the next 33 bytes onto the stack.
22	OP_DATA_34	Push	Pushes the next 34 bytes onto the stack.
23	OP_DATA_35	Push	Pushes the next 35 bytes onto the stack.
24	OP_DATA_36	Push	Pushes the next 36 bytes onto the stack.
25	OP_DATA_37	Push	Pushes the next 37 bytes onto the stack.
26	OP_DATA_38	Push	Pushes the next 38 bytes onto the stack.
27	OP_DATA_39	Push	Pushes the next 39 bytes onto the stack.
28	OP_DATA_40	Push	Pushes the next 40 bytes onto the stack.
29	OP_DATA_41	Push	Pushes the next 41 bytes onto the stack.
2a	OP_DATA_42	Push	Pushes the next 42 bytes onto the stack.
2b	OP_DATA_43	Push	Pushes the next 43 bytes onto the stack.
2c	OP_DATA_44	Push	Pushes the next 44 bytes onto the stack.
2d	OP_DATA_45	Push	Pushes the next 45 bytes onto the stack.
2e	OP_DATA_46	Push	Pushes the next 46 bytes onto the stack.
2f	OP_DATA_47	Push	Pushes the next 47 bytes onto the stack.
30	OP_DATA_48	Push	Pushes the next 48 bytes onto the stack.
31	OP_DATA_49	Push	Pushes the next 49 bytes onto the stack.
32	OP_DATA_50	Push	Pushes the next 50 bytes onto the stack.
33	OP_DATA_51	Push	Pushes the next 51 bytes onto the stack.
34	OP_DATA_52	Push	Pushes the next 52 bytes onto the stack.
35	OP_DATA_53	Push	Pushes the next 53 bytes onto the stack.
36	OP_DATA_54	Push	Pushes the next 54 bytes onto the stack.
37	OP_DATA_55	Push	Pushes the next 55 bytes onto the stack.
38	OP_DATA_56	Push	Pushes the next 56 bytes onto the stack.
39	OP_DATA_57	Push	Pushes the next 57 bytes onto the stack.
3a	OP_DATA_58	Push	Pushes the next 58 bytes onto the stack.
3b	OP_DATA_59	Push	Pushes the next 59 bytes onto the stack.
3c	OP_DATA_60	Push	Pushes the next 60 bytes onto the stack.
3d	OP_DATA_61	Push	Pushes the next 61 bytes onto the stack.
3e	OP_DATA_62	Push	Pushes the next 62 bytes onto the stack.
3f	OP_DATA_63	Push	Pushes the next 63 bytes onto the stack.
40	OP_DATA_64	Push	Pushes the next 64 bytes onto the stack.
41	OP_DATA_65	Push	Pushes the next 65 bytes onto the stack.
42	OP_DATA_66	Push	Pushes the next 66 bytes onto the stack.
43	OP_DATA_67	Push	Pushes the next 67 bytes onto the stack.
44	OP_DATA_68	Push	Pushes the next 68 bytes onto the stack.
45	OP_DATA_69	Push	Pushes the next 69 bytes onto the stack.
46	OP_DATA_70	Push	Pushes the next 70 bytes onto the stack.
47	OP_DATA_71	Push	Pushes the next 71 bytes onto the stack.
48	OP_DATA_72	Push	Pushes the next 72 bytes onto the stack.
49	OP_DATA_73	Push	Pushes the next 73 bytes onto the stack.
4a	OP_DATA_74	Push	Pushes the next 74 bytes onto the stack.
4b	OP_DATA_75	Push	Pushes the next 75 bytes onto the stack.
4c	OP_PUSHDATA1	Push	The next byte says how many bytes to push (up to 255).
4d	OP_PUSHDATA2	Push	The next 2 bytes (little-endian) say how many bytes to push.
4e	OP_PUSHDATA4	Push	The next 4 bytes (little-endian) say how many bytes to push.
4f	OP_1NEGATE	Push	Pushes the number -1.
50	OP_RESERVED	Fails if run	Reserved: the script fails if it is executed.
51	OP_1	Push	Pushes the number 1. Also the witness-version byte of a Taproot output (5120…).
52	OP_2	Push	Pushes the number 2. Also the witness-version byte of a P2MR output (5220…).
53	OP_3	Push	Pushes the number 3.
54	OP_4	Push	Pushes the number 4.
55	OP_5	Push	Pushes the number 5.
56	OP_6	Push	Pushes the number 6.
57	OP_7	Push	Pushes the number 7.
58	OP_8	Push	Pushes the number 8.
59	OP_9	Push	Pushes the number 9.
5a	OP_10	Push	Pushes the number 10.
5b	OP_11	Push	Pushes the number 11.
5c	OP_12	Push	Pushes the number 12.
5d	OP_13	Push	Pushes the number 13.
5e	OP_14	Push	Pushes the number 14.
5f	OP_15	Push	Pushes the number 15.
60	OP_16	Push	Pushes the number 16.
61	OP_NOP	Works	Does nothing.
62	OP_VER	Fails if run	Reserved: the script fails if it is executed.
63	OP_IF	Works	Runs the following code only if the top stack item is true (must be exactly empty or 0x01 in tapscript).
64	OP_NOTIF	Works	Runs the following code only if the top stack item is false.
65	OP_VERIF	Disabled	Always illegal, even in a branch that is not executed.
66	OP_VERNOTIF	Disabled	Always illegal, even in a branch that is not executed.
67	OP_ELSE	Works	Switches to the other branch of an OP_IF / OP_NOTIF.
68	OP_ENDIF	Works	Ends an OP_IF / OP_NOTIF block.
69	OP_VERIFY	Works	Fails the script unless the top item is true; removes it.
6a	OP_RETURN	Works	Ends the script as failed. An output script starting with OP_RETURN is a provably unspendable data carrier.
6b	OP_TOALTSTACK	Works	Moves the top item to the alt stack.
6c	OP_FROMALTSTACK	Works	Moves the top alt-stack item back to the main stack.
6d	OP_2DROP	Works	Removes the top two items.
6e	OP_2DUP	Works	Duplicates the top two items.
6f	OP_3DUP	Works	Duplicates the top three items.
70	OP_2OVER	Works	Copies the pair of items two spaces back to the top.
71	OP_2ROT	Works	Moves the fifth and sixth items to the top.
72	OP_2SWAP	Works	Swaps the top two pairs of items.
73	OP_IFDUP	Works	Duplicates the top item if it is not zero.
74	OP_DEPTH	Works	Pushes the number of stack items.
75	OP_DROP	Works	Removes the top item.
76	OP_DUP	Works	Duplicates the top item.
77	OP_NIP	Works	Removes the second-to-top item.
78	OP_OVER	Works	Copies the second-to-top item to the top.
79	OP_PICK	Works	Copies the item n back to the top.
7a	OP_ROLL	Works	Moves the item n back to the top.
7b	OP_ROT	Works	Rotates the top three items to the left.
7c	OP_SWAP	Works	Swaps the top two items.
7d	OP_TUCK	Works	Copies the top item below the second item.
7e	OP_CAT	Tapscript only	Concatenates the top two items (result at most 520 bytes).
7f	OP_SUBSTR	Disabled	Disabled: its mere presence makes the script invalid.
80	OP_LEFT	Disabled	Disabled: its mere presence makes the script invalid.
81	OP_RIGHT	Disabled	Disabled: its mere presence makes the script invalid.
82	OP_SIZE	Works	Pushes the byte length of the top item.
83	OP_INVERT	Disabled	Disabled: its mere presence makes the script invalid.
84	OP_AND	Disabled	Disabled: its mere presence makes the script invalid.
85	OP_OR	Disabled	Disabled: its mere presence makes the script invalid.
86	OP_XOR	Disabled	Disabled: its mere presence makes the script invalid.
87	OP_EQUAL	Works	Pushes true if the top two items are byte-for-byte equal.
88	OP_EQUALVERIFY	Works	OP_EQUAL then OP_VERIFY.
89	OP_RESERVED1	Fails if run	Reserved: the script fails if it is executed.
8a	OP_RESERVED2	Fails if run	Reserved: the script fails if it is executed.
8b	OP_1ADD	Works	Adds 1 to the top number.
8c	OP_1SUB	Works	Subtracts 1 from the top number.
8d	OP_2MUL	Disabled	Disabled: its mere presence makes the script invalid.
8e	OP_2DIV	Disabled	Disabled: its mere presence makes the script invalid.
8f	OP_NEGATE	Works	Flips the sign of the top number.
90	OP_ABS	Works	Replaces the top number with its absolute value.
91	OP_NOT	Works	Turns 0 into 1 and anything else into 0.
92	OP_0NOTEQUAL	Works	Turns 0 into 0 and anything else into 1.
93	OP_ADD	Works	Adds the top two numbers.
94	OP_SUB	Works	Subtracts the top number from the second.
95	OP_MUL	Disabled	Disabled: its mere presence makes the script invalid.
96	OP_DIV	Disabled	Disabled: its mere presence makes the script invalid.
97	OP_MOD	Disabled	Disabled: its mere presence makes the script invalid.
98	OP_LSHIFT	Disabled	Disabled: its mere presence makes the script invalid.
99	OP_RSHIFT	Disabled	Disabled: its mere presence makes the script invalid.
9a	OP_BOOLAND	Works	Pushes 1 if both top numbers are non-zero.
9b	OP_BOOLOR	Works	Pushes 1 if either top number is non-zero.
9c	OP_NUMEQUAL	Works	Pushes 1 if the top two numbers are equal.
9d	OP_NUMEQUALVERIFY	Works	OP_NUMEQUAL then OP_VERIFY.
9e	OP_NUMNOTEQUAL	Works	Pushes 1 if the top two numbers differ.
9f	OP_LESSTHAN	Works	Pushes 1 if the second number is less than the top.
a0	OP_GREATERTHAN	Works	Pushes 1 if the second number is greater than the top.
a1	OP_LESSTHANOREQUAL	Works	Pushes 1 if the second number is ≤ the top.
a2	OP_GREATERTHANOREQUAL	Works	Pushes 1 if the second number is ≥ the top.
a3	OP_MIN	Works	Keeps the smaller of the top two numbers.
a4	OP_MAX	Works	Keeps the larger of the top two numbers.
a5	OP_WITHIN	Works	Pushes 1 if x is within [min, max).
a6	OP_RIPEMD160	Works	Replaces the top item with its RIPEMD-160 hash.
a7	OP_SHA1	Works	Replaces the top item with its SHA-1 hash.
a8	OP_SHA256	Works	Replaces the top item with its SHA-256 hash.
a9	OP_HASH160	Works	Replaces the top item with RIPEMD160(SHA256(x)).
aa	OP_HASH256	Works	Replaces the top item with SHA256(SHA256(x)).
ab	OP_CODESEPARATOR	Works	Records its position, which signatures then commit to (BIP-342 codesep_pos).
ac	OP_CHECKSIG	Tapscript only	Checks a Schnorr signature against a 32-byte x-only key; empty signature pushes false.
ad	OP_CHECKSIGVERIFY	Tapscript only	OP_CHECKSIG then OP_VERIFY.
ae	OP_CHECKMULTISIG	Fails if run	Always fails in Pearl (use OP_CHECKSIGADD instead).
af	OP_CHECKMULTISIGVERIFY	Fails if run	Always fails in Pearl.
b0	OP_NOP1	Fails if run	Reserved for upgrades: fails when executed.
b1	OP_CHECKLOCKTIMEVERIFY	Works	Fails unless the transaction locktime has reached the given height/time (BIP-65).
b2	OP_CHECKSEQUENCEVERIFY	Works	Fails unless the input has aged by the given relative lock (BIP-112, needs tx version ≥ 2).
b3	OP_NOP4	Fails if run	Reserved for upgrades: fails when executed.
b4	OP_NOP5	Fails if run	Reserved for upgrades: fails when executed.
b5	OP_NOP6	Fails if run	Reserved for upgrades: fails when executed.
b6	OP_NOP7	Fails if run	Reserved for upgrades: fails when executed.
b7	OP_NOP8	Fails if run	Reserved for upgrades: fails when executed.
b8	OP_NOP9	Fails if run	Reserved for upgrades: fails when executed.
b9	OP_NOP10	Fails if run	Reserved for upgrades: fails when executed.
ba	OP_CHECKSIGADD	Tapscript only	Checks a signature and adds 1 to a counter if it is valid: the building block of k-of-n multisig (BIP-342).
bb	OP_UNKNOWN187	Fails if run	Undefined opcode: the script fails if it is executed.
bc	OP_UNKNOWN188	Fails if run	Undefined opcode: the script fails if it is executed.
bd	OP_UNKNOWN189	Fails if run	Undefined opcode: the script fails if it is executed.
be	OP_UNKNOWN190	Fails if run	Undefined opcode: the script fails if it is executed.
bf	OP_UNKNOWN191	Fails if run	Undefined opcode: the script fails if it is executed.
c0	OP_UNKNOWN192	Fails if run	Undefined opcode: the script fails if it is executed.
c1	OP_UNKNOWN193	Fails if run	Undefined opcode: the script fails if it is executed.
c2	OP_UNKNOWN194	Fails if run	Undefined opcode: the script fails if it is executed.
c3	OP_UNKNOWN195	Fails if run	Undefined opcode: the script fails if it is executed.
c4	OP_UNKNOWN196	Fails if run	Undefined opcode: the script fails if it is executed.
c5	OP_UNKNOWN197	Fails if run	Undefined opcode: the script fails if it is executed.
c6	OP_UNKNOWN198	Fails if run	Undefined opcode: the script fails if it is executed.
c7	OP_UNKNOWN199	Fails if run	Undefined opcode: the script fails if it is executed.
c8	OP_UNKNOWN200	Fails if run	Undefined opcode: the script fails if it is executed.
c9	OP_UNKNOWN201	Fails if run	Undefined opcode: the script fails if it is executed.
ca	OP_UNKNOWN202	Fails if run	Undefined opcode: the script fails if it is executed.
cb	OP_UNKNOWN203	Fails if run	Undefined opcode: the script fails if it is executed.
cc	OP_UNKNOWN204	Fails if run	Undefined opcode: the script fails if it is executed.
cd	OP_UNKNOWN205	Fails if run	Undefined opcode: the script fails if it is executed.
ce	OP_UNKNOWN206	Fails if run	Undefined opcode: the script fails if it is executed.
cf	OP_UNKNOWN207	Fails if run	Undefined opcode: the script fails if it is executed.
d0	OP_UNKNOWN208	Fails if run	Undefined opcode: the script fails if it is executed.
d1	OP_UNKNOWN209	Fails if run	Undefined opcode: the script fails if it is executed.
d2	OP_UNKNOWN210	Fails if run	Undefined opcode: the script fails if it is executed.
d3	OP_UNKNOWN211	Fails if run	Undefined opcode: the script fails if it is executed.
d4	OP_UNKNOWN212	Fails if run	Undefined opcode: the script fails if it is executed.
d5	OP_UNKNOWN213	Fails if run	Undefined opcode: the script fails if it is executed.
d6	OP_UNKNOWN214	Fails if run	Undefined opcode: the script fails if it is executed.
d7	OP_UNKNOWN215	Fails if run	Undefined opcode: the script fails if it is executed.
d8	OP_UNKNOWN216	Fails if run	Undefined opcode: the script fails if it is executed.
d9	OP_UNKNOWN217	Fails if run	Undefined opcode: the script fails if it is executed.
da	OP_UNKNOWN218	Fails if run	Undefined opcode: the script fails if it is executed.
db	OP_UNKNOWN219	Fails if run	Undefined opcode: the script fails if it is executed.
dc	OP_UNKNOWN220	Fails if run	Undefined opcode: the script fails if it is executed.
dd	OP_UNKNOWN221	Fails if run	Undefined opcode: the script fails if it is executed.
de	OP_CHECKXMSSSIG	Tapscript only	Checks a post-quantum XMSS signature: stack [sig1…sig5 (468 B each), 64-byte pubkey] → [true]; an invalid signature fails the script.
df	OP_UNKNOWN223	Fails if run	Undefined opcode: the script fails if it is executed.
e0	OP_UNKNOWN224	Fails if run	Undefined opcode: the script fails if it is executed.
e1	OP_UNKNOWN225	Fails if run	Undefined opcode: the script fails if it is executed.
e2	OP_UNKNOWN226	Fails if run	Undefined opcode: the script fails if it is executed.
e3	OP_UNKNOWN227	Fails if run	Undefined opcode: the script fails if it is executed.
e4	OP_UNKNOWN228	Fails if run	Undefined opcode: the script fails if it is executed.
e5	OP_UNKNOWN229	Fails if run	Undefined opcode: the script fails if it is executed.
e6	OP_UNKNOWN230	Fails if run	Undefined opcode: the script fails if it is executed.
e7	OP_UNKNOWN231	Fails if run	Undefined opcode: the script fails if it is executed.
e8	OP_UNKNOWN232	Fails if run	Undefined opcode: the script fails if it is executed.
e9	OP_UNKNOWN233	Fails if run	Undefined opcode: the script fails if it is executed.
ea	OP_UNKNOWN234	Fails if run	Undefined opcode: the script fails if it is executed.
eb	OP_UNKNOWN235	Fails if run	Undefined opcode: the script fails if it is executed.
ec	OP_UNKNOWN236	Fails if run	Undefined opcode: the script fails if it is executed.
ed	OP_UNKNOWN237	Fails if run	Undefined opcode: the script fails if it is executed.
ee	OP_UNKNOWN238	Fails if run	Undefined opcode: the script fails if it is executed.
ef	OP_UNKNOWN239	Fails if run	Undefined opcode: the script fails if it is executed.
f0	OP_UNKNOWN240	Fails if run	Undefined opcode: the script fails if it is executed.
f1	OP_UNKNOWN241	Fails if run	Undefined opcode: the script fails if it is executed.
f2	OP_UNKNOWN242	Fails if run	Undefined opcode: the script fails if it is executed.
f3	OP_UNKNOWN243	Fails if run	Undefined opcode: the script fails if it is executed.
f4	OP_UNKNOWN244	Fails if run	Undefined opcode: the script fails if it is executed.
f5	OP_UNKNOWN245	Fails if run	Undefined opcode: the script fails if it is executed.
f6	OP_UNKNOWN246	Fails if run	Undefined opcode: the script fails if it is executed.
f7	OP_UNKNOWN247	Fails if run	Undefined opcode: the script fails if it is executed.
f8	OP_UNKNOWN248	Fails if run	Undefined opcode: the script fails if it is executed.
f9	OP_UNKNOWN249	Fails if run	Undefined opcode: the script fails if it is executed.
fa	OP_SMALLINTEGER	Fails if run	Internal template name, not a real opcode: fails when executed.
fb	OP_PUBKEYS	Fails if run	Internal template name, not a real opcode: fails when executed.
fc	OP_UNKNOWN252	Fails if run	Undefined opcode: the script fails if it is executed.
fd	OP_PUBKEYHASH	Fails if run	Internal template name, not a real opcode: fails when executed.
fe	OP_PUBKEY	Fails if run	Internal template name, not a real opcode: fails when executed.
ff	OP_INVALIDOPCODE	Fails if run	Invalid opcode: fails when executed.