Cambridge IGCSE & O Level · all 23 ExamForge subjects
Cambridge mark scheme abbreviations, explained
What nfww, oe, cao, FT, owtte, ecf, AVP and the rest actually mean, split by subject, with Cambridge’s own wording and a real line from a real mark scheme for each.
Quick answers
- nfww
- not from wrong working: the answer only scores if the working that led to it is correct.
- oe
- or equivalent: any equal form counts (3/4, 0.75, 75%).
- cao
- correct answer only: exactly this answer, nothing carried through.
- FT / ft
- follow through after error: your own earlier answer, used correctly, still scores.
- owtte
- or words to that effect: your own wording is fine if it means the same.
- ecf
- error carried forward: a wrong earlier value, used correctly, still earns later marks.
Same letter, different meaning
Cambridge does not use one list for every subject. These three catch students out most:
M1
Maths: a method mark.
Chemistry: marking point 1, not a method.
A
Maths: accuracy mark.
Physics: final answer including the unit.
Biology: “accept the response”.
C
Physics only: a compensatory mark you can still score when the final answer is wrong.
By subject
Pick your subject. Definitions are quoted from Cambridge’s own 2025 mark schemes.
Mathematics & Additional Mathematics
Types of mark + Abbreviations tables, identical in all four syllabuses- M1, M28,147 uses
The right approach scores, even if the arithmetic slips later.
Cambridge: “Method marks, awarded for a valid method applied to the problem.”
M1 for mid-points soi
0580 · Feb/Mar 2024 · P22 · Q17
- A1, A2735 uses
The correct answer or step, only once the method is there.
Cambridge: “Accuracy mark … the associated Method mark must be earned or implied.”
A1 for 244.9 to 245.2
0580 · Feb/Mar 2024 · P42 · Q6
- B1, B25,337 uses
Stands alone: the right value scores on its own.
Cambridge: “Mark for a correct result or statement independent of Method marks.”
B1 for 3m or 10k in final answer
0580 · Feb/Mar 2024 · P12 · Q9
- dep373 uses
You only get it if you already got the earlier mark.
Cambridge: “dependent: a particular M or B mark is dependent on an earlier mark.”
dep on at least M1
0580 · Feb/Mar 2024 · P22 · Q26
- oe6,204 uses
Any equal form counts: 3/4, 0.75, 75%.
Cambridge: “or equivalent”
B1 for 8400 oe seen
0580 · Feb/Mar 2024 · P12 · Q22
- cao576 uses
Exactly this answer; nothing carried through.
Cambridge: “correct answer only”
[$]10935 cao
0580 · May/Jun 2024 · P32 · Q7
- nfww358 uses
A right answer only scores if the working is right too.
Cambridge: “not from wrong working”
B2 for BX = 18 nfww
0580 · Feb/Mar 2024 · P42 · Q2
- FT751 uses
Your earlier wrong answer, used correctly, still scores.
Cambridge: “follow through after error”
FT 0.75 × their 360
0580 · Feb/Mar 2024 · P42 · Q1
- isw160 uses
Extra working after the right answer isn't penalised.
Cambridge: “ignore subsequent working”
marked on diagram at C isw
0580 · Feb/Mar 2025 · P42 · Q17
- soi542 uses
Write the step, or show it through what you do next.
Cambridge: “seen or implied”
(0.4 0.9 3.5 2 0.5) soi
0580 · Feb/Mar 2024 · P42 · Q3
- awrt160 (0606) uses
Any answer that rounds to this value scores.
Cambridge: “answers which round to”
awrt 6.2 to awrt 6.4 isw
0606 · Feb/Mar 2024 · P22 · Q8
- rot106 (0606) uses
Rounded or cut-off values are both accepted.
Cambridge: “rounded or truncated”
0.955 or 0.9553[1...] rot to 4 or more sf
0606 · Feb/Mar 2024 · P22 · Q4
- SC865 uses
A consolation mark spelled out in the scheme, often only if you'd otherwise score 0.
Cambridge: “Special Case”
If 0 scored SC1 for 3, 2, 1
0580 · Feb/Mar 2024 · P12 · Q20
Uses = times the code appears in 0580 mark schemes, 2016–2025 (0606 where marked).
Misread rule: if you misread a number and use it consistently, without making the question easier, you lose just 1 A or B mark. Also seen in Additional Maths but not in the printed table: www (without wrong working) and cso (correct solution only).
Practise by topic:Mathematics 0580Additional Mathematics 0606Mathematics (Syllabus D) 4024Additional Mathematics 4037
Physics
“Acronyms and shorthand in the mark scheme” table- A mark1,607 uses
Wrong or missing unit? This mark goes.
Cambridge: “Final answer mark which is awarded for fully correct final answers including the unit.”
- C mark2,209 uses
Final answer wrong? A correct equation or substitution still rescues a mark.
Cambridge: “Compensatory mark which may be scored when the final answer (A) mark … has not been awarded.”
P = V I OR (I =) P ÷ V OR (I =) 25 ÷ 230 C1
0625 · May/Jun 2025 · Paper 42
- B mark6,158 uses
Scores on its own.
Cambridge: “Independent mark which does not depend on any other mark.”
alpha (particles) would be absorbed / stopped by the skin owtte B1
0625 · May/Jun 2025 · Paper 42 · 9(b)(ii)
- M mark187 uses
No method mark, no answer mark after it.
Cambridge: “Method mark which must be scored before any subsequent final answer (A) mark can be scored.”
- owtte359 uses
Your own wording is fine if the physics is the same.
Cambridge: “Or words to that effect.”
alpha (particles) would be absorbed / stopped by the skin owtte
0625 · May/Jun 2025 · Paper 42 · 9(b)(ii)
- ORA36 uses
Saying it the other way round also scores.
Cambridge: “Or reverse argument.”
field lines close(r) indicates strong(er) (magnetic) field owtte ORA
0625 · May/Jun 2025 · Paper 41 · 6(d)
- ecf [part]64 uses
A wrong value from an earlier part, used correctly, still scores.
Cambridge: “A candidate using an erroneous value from the stated question part must be given credit here if … used correctly.”
correct calculations of R … / ecf
0625 · Feb/Mar 2017 · Paper 62 · Q2
- ( )
Optional words, but don't contradict them.
Cambridge: “Words not explicitly needed … if a contradictory word / phrase / unit … is seen the mark is not awarded.”
(distance =) area under graph
0625 · May/Jun 2025 · Paper 42
- underline
Key word required; technical terms exactly.
Cambridge: “The underlined word (or a synonym) must be present for the mark to be scored.”
- / or OR
Any one of these scores.
Cambridge: “Alternative answers any one of which gains the credit for that mark.”
- ignore7 uses
That extra bit doesn't cost you.
Cambridge: “An incorrect or irrelevant point which may be disregarded, i.e., not treated as contradictory.”
current NOT amps ignore ammeter
0625 · May/Jun 2018 · Paper 31 · Q10
- insufficient36 (5054) uses
Right direction, not enough for the mark.
Cambridge: “An answer not worthy of credit on its own.”
- CONseen uses
A wrong statement next to a right one cancels it.
Cambridge: “An incorrect point which contradicts any correct point and means the mark cannot be scored.”
- cao4 uses
Exactly this answer.
Cambridge: “Correct answer only.”
Uses = times the code appears in 0625 mark schemes, 2016–2025 (5054 where marked).
Physics A ≠ Biology A. Here an A mark is the final answer including its unit; in Biology lists A means “accept”. Science rule (all sciences): a missing or incorrect unit will normally mean the final calculation mark is not awarded.
Practise by topic:Physics 0625Physics 5054
Chemistry
No abbreviation table is printed (2019–2025); this is the notation used in the scheme itself- M1, M2 …3,248 uses
In Chemistry M1 means marking point 1, NOT a method mark.
Cambridge: “Numbered marking points (no printed definition).”
M1 CaO is basic
0620 · Feb/Mar 2024 · Paper 42 · Q1
- ;
Each part between semicolons is its own mark.
Cambridge: “Separates marking points.”
- /
Any one of these scores.
Cambridge: “Alternatives for the same point.”
- ignore15 uses
Neither helps nor hurts.
Cambridge: “Disregard this part of the answer.”
gold does not react (ignore products with pyrites) / ora;
0620 · Feb/Mar 2016 · Paper 42 · Q6
- max120 uses
Extra points beyond this score nothing.
Cambridge: “Maximum marks from a list of points.”
physical properties [max 3], e.g.:
0620 · Feb/Mar 2017 · Paper 32 · Q7
- ORA174 uses
Saying it the other way round also scores.
Cambridge: “Or reverse argument.”
M3 weaker attraction (between particles) in F2 ORA (1)
0620 · May/Jun 2024 · Paper 41 · Q3
- insufficient46 (PDFs) uses
Right idea, not enough detail.
Cambridge: “Not creditworthy on its own.”
- CON35 (PDFs) uses
Cancels the mark.
Cambridge: “Contradicts a correct point.”
Uses = times the code appears in 0620 mark schemes, 2016–2025 (2023–25 PDFs where marked).
Science rules from Cambridge’s 2025 schemes: spellings needn’t be perfect, but syllabus terms must be unambiguous (ethane / ethene). In “State two…” questions, incorrect responses still count towards the two. Multiples / fractions of equation coefficients are accepted; state symbols are ignored unless asked for.
Practise by topic:Chemistry 0620Chemistry 5070
Biology, Combined & Co-ordinated Science, Environmental Management
“Mark Scheme Abbreviations” table (0610, 5090, 0653)- ;
Each part between semicolons is a separate mark.
Cambridge: “separates marking points”
medium for cell reactions / site of chemical reactions / AW ;
0610 · Feb/Mar 2024 · P32 · Q1
- /
Any one of these scores the same mark.
Cambridge: “alternative responses for the same marking point”
- R
This answer gets nothing.
Cambridge: “reject the response”
R letter B
0610 · Feb/Mar 2024 · P32 · Q3
- A
This answer also scores.
Cambridge: “accept the response”
A atrioventricular valve ;
0610 · Feb/Mar 2024 · P42 · Q2
- I
Neither helps nor hurts.
Cambridge: “ignore the response”
- ecf279 uses
Your earlier wrong value, used correctly, still scores.
Cambridge: “error carried forward”
use ecf from each previous step throughout
0610 · Feb/Mar 2024 · P32 · Q3
- AVP1,020 uses
Another correct point of the same kind scores.
Cambridge: “any valid point”
biofuels / AVP ;
0610 · May/Jun 2024 · P31 · Q1
- ora432 uses
The opposite way round also scores.
Cambridge: “or reverse argument”
anthers / stigma, inside petals / flower / ora ;
0610 · Feb/Mar 2024 · P42 · Q5
- AW1,830 uses
Different words, same meaning, still scores.
Cambridge: “alternative wording”
optimum environment for organelles / AW ;
0610 · Feb/Mar 2024 · P32 · Q1
- underline
That exact word must appear.
Cambridge: “actual word given must be used by candidate (grammatical variants excepted)”
- ( )
Optional words.
Cambridge: “the word / phrase in brackets is not required but sets the context”
- max181 uses
The cap for this list of points.
Cambridge: “indicates the maximum number of marks that can be given”
max 3 marks from advantages or disadvantages
0610 · Feb/Mar 2024 · P42 · Q5
- MP
One creditable point.
Cambridge: “marking point”
ecf from previous MP if evidenced
0610 · May/Jun 2024 · P41 · Q6
Uses = times the code appears in 0610 mark schemes, 2016–2025.
Biology A ≠ Physics A: here A simply means accept. 0654 and 0680 don’t print the table but use the same codes (0654: AVP 162, AW 127). Environmental Management also numbers marking points M1, M2… and uses levels for longer answers.
Practise by topic:Biology 0610Biology 5090Combined Science 0653Co-ordinated Sciences 0654Environmental Management 0680
Computer Science & ICT
“Mark scheme abbreviations” table- /
Any of these words works inside the point.
Cambridge: “separates alternative words / phrases within a marking point”
- //
Either whole answer scores.
Cambridge: “separates alternative answers within a marking point”
It can run 3.5 billion FE cycles each second // it can execute 3.5 billion instructions each second
0478 · Feb/Mar 2024 · P12 · Q2
- underline
That exact word must appear.
Cambridge: “actual word given must be used by candidate (grammatical variants accepted)”
- max258 uses
The cap for this question part.
Cambridge: “indicates the maximum number of marks that can be awarded”
One mark for each point max four.
0478 · Feb/Mar 2024 · P22 · Q3
- ( )
Optional words.
Cambridge: “the word / phrase in brackets is not required, but sets the context”
- SEEN · NR · NAQ
Blank = no response; writing something that isn't an answer scores 0.
Cambridge: “If an answer is left blank then use SEEN and award NR … if anything has been written (e.g. ‘Don’t know’, ‘?’) then use NAQ and award 0.”
0417 · Feb/Mar 2024 · P12 (front matter)
Uses = times the code appears in 0478 mark schemes, 2016–2025.
Cambridge’s note in both schemes: no marks are awarded for using brand names of software packages or hardware.
Practise by topic:Computer Science 0478ICT 0417
Economics, Business Studies & Accounting
Generic marking principles + levels of response- OF1,622 (0452) uses
Your wrong number from earlier, with the right method, still gets full marks.
Cambridge: “Own figure rule: full marks will be given if a correct and complete method is used with the candidate’s own incorrect figure.”
Income and expenditure (1)OF
0452 · Feb/Mar 2024 · P22 · Q3
- (1)
Each (1) is one mark.
Cambridge: “One mark for this point.”
Income and expenditure (1)OF
0452 · Feb/Mar 2024 · P22 · Q3
- app · an
app = tied to the case business; an = a developed consequence.
Cambridge: “Application · analysis (skill tags on Business answers).”
help SC to expand the business and increase the sales of its cars abroad (app)
0450 · May/Jun 2017 · P23 · Q1
- Level 1–3223 (0264) uses
Longer answers are placed in a level first, then marked within it.
Cambridge: “Levels of response.”
Level 3 – For L3 to be awarded there needs to be at least two L2 marks
0450 · Feb/Mar 2017 · P22 · Q2
- max1,102 (0264) uses
Points beyond the cap score nothing.
Cambridge: “Maximum marks for a list of points.”
Award 1 mark for each relevant reason (max 2).
0450 · Feb/Mar 2024 · P12 · Q1
- BOD2 (0455) uses
Borderline, but credited.
Cambridge: “Benefit of the doubt.”
Give BOD if answer states GDP alone
0455 · May/Jun 2022 · P23 · Q1
Uses = times the code appears in that subject’s mark schemes, 2016–2025.
Cambridge: for levels of response marking, the level awarded is annotated on the script, and ticks have no defined meaning for levels. Business questions tag points by skill: knowledge, application (app), analysis (an), evaluation.
Practise by topic:Economics 0455Economics 2281Business StudiesBusiness Studies 7115Accounting 0452Accounting 7707
Islamiyat & Islamic Studies
Levels of response grids (no abbreviations)- Level 1–4
Your answer gets a level, then a mark inside it.
Cambridge: “Marks are awarded according to the four levels of response for each AO, following the level descriptors.”
Level 4 answers should have most of this
0493 · May/Jun 2018 · P11 · Q3
- AO1
What you know and how accurately you explain it.
Cambridge: “Knowledge and understanding.”
Level 4 (9–10): Answers most aspects of the question, using a range of detailed, accurate and relevant knowledge.
2068 · May/Jun 2025 · P12 · Table A
- Positive awarding
You're marked on what you get right, not on what's missing.
Cambridge: “Marks should be awarded for appropriate responses to reasonable interpretations of the question.”
0493 · May/Jun 2025 · P11
These schemes use level descriptors instead of abbreviation codes.
No abbreviation codes: answers are placed in a level using the level descriptors, then given a mark within that level.
Practise by topic:Islamiyat 0493Islamic Studies 2068
Words almost every subject uses
- accept / allow / A
- : this answer also scores.
- ignore / I
- : this part is disregarded; it neither helps nor hurts.
- reject / R / NOT
- : this answer gets no credit.
- max
- : the most marks you can get from this list of points.
- insufficient
- : on the right lines, but not enough for the mark.
- BOD
- : benefit of the doubt; borderline, but credited.
Reading a real scheme line by line
This is Maths 0580 October/November 2025, Paper 13, Question 8. Each code tells you exactly how the marks are released.
- M1 … oe: the method (180 − 108) scores, written in any equivalent form.
- A1 nfww: the answer mark only comes if the working above is right.
- B1dep: an independent mark that depends on the earlier mark being earned.
Maths 0580 · ON25_13 Q8 · 7 marks
What the mark scheme says
M1 for 180 − 108 oe
A1 nfww
B1dep for correct method seen
Common questions
What does nfww mean in a mark scheme?
Not from wrong working. The answer mark is only given if the working leading to it is correct, so a right answer reached by a wrong method scores nothing for that mark.
What does oe mean?
Or equivalent: any form with the same value is accepted.
What does cao mean?
Correct answer only: exactly the stated answer, with no follow-through from earlier mistakes.
What is the difference between M1 and A1?
In Maths, M1 is for a valid method; A1 is for the correct answer and only counts if the method mark is earned or implied. In Chemistry, M1 just means marking point 1.
What does owtte mean?
Or words to that effect: a different phrasing with the same meaning gets the mark.
What does ecf mean?
Error carried forward: if you use a wrong earlier value correctly, you still get the later marks.
What does AVP mean in Biology?
Any valid point: another correct point of the same kind also scores.
Definitions quoted from Cambridge’s published 2025 mark schemes for each subject. “Uses” counts how often each code appears in the mark schemes in the ExamForge bank (2016–2025); O Level counts come from 2023–2025 schemes. How the data is built