Spell out numbers below 10: one, nine, first fourth, 17th, 123rd, 999. One million, two million, 10 million, 999 million. Give broken millions in full only when it is misleading to decimalise to two places; 2,736,123 but prefer 2.74 million. If possible leave a thin space between the number and the "million".

One billion (= 1,000 million), two billion, 25 billion. Avoid using billion if only one or two figures in a series exceed 999 million; then write, say, 1,345 million. Avoid trillion (= million million).

Use figures at all times with currency signs and abbreviations: £1, $2. Abbreviate million to m and billion to bn in headlines.

In stories concerned mainly with money, company reports and City page references to bids and deals, use m and bn. In news stories as distinct from stories in the business section always write million and billion in full.

Decimal points: these are to appear at the bottom of numbers, not half way up them.

Money: 1p, 99p, £1, £1.33. Only pounds, United States dollars and the euro take symbols in general news and feature copy. All other currencies are anglicised: first mention Swiss francs, Canadian Dollars, Turkish lire and so on, then, francs, dollars etc.

In lists on City pages and when it has been established which currency is being referred to, these abbreviations may be used: Australia A$, Canada C$, Hong Kong HK$, India Rs, Israel Shl, Japan Y, Saudi Arabia SR, South Africa R, Switzerland Sfr. The plural of lira is lire. Sweden has the krona (Skr) with the plural kronor, Norway the krone (Nkr) with the plural kroner, and Denmark the krone (Dkr) with the plural kroner.

Give sterling equivalents in brackets after references to foreign currencies. If writing a story that includes reference to the pre-decimal coinage, use the following abbreviations: £ for pound, s for shilling and d for pence as in £7 15s 6d. There were four farthings in a penny, 12 pence in a shilling and 20 shillings in a pound, 21 shillings in a guinea. A 2s piece was a florin, a 2s 6d piece a half-crown, and there were five shillings in a crown.

Use common British weights and measures even in foreign stories unless the context dictates otherwise. Metric weights and measures should be followed by British equivalents in brackets. Use the abbreviations oz, lb, st, cwt, in, ft, yd after numerals from two upwards. No full points, no plurals, no space between the number and the abbreviation.

Do not abbreviate acres, miles, pints, gallons. One pound, less than a hundredweight, a few ounces, 7lb, 5st, l0st 5lb, 5lb 7oz. Two miles, 27 miles, two acres, 125 acres, 2ft, 2ft 3in, 3yd, 3yd 2ft, two square yards, 22 sq yd.

Usually it is not necessary to distinguish between the ton (imperial, 2240lb) and the tonne (metric ton of 1,000 kilograms = 2,204.6lb). Use tons unless the small difference is important.

Fractions: use half, quarter, three quarters, third, fifth, eighth in preference to decimals in general copy. Use decimals when they aid comprehension or comparison, but not with imperial measurements: e.g. write 3ft 9in rather than 3.75 feet, or 6lb 8oz not 6.5lb. Do not use decimals and fractions in the same story except when necessary in financial copy. In money markets all dealings are in fractions. Write 2¼, but one-quarter per cent.

If it is necessary to use oddities such as two one-hundredths of a second, ensure that the use of the hyphen and the word "one" prevents confusion with two hundredths. Two 100ths of a second or 200th of a second are ugly, but may be necessary.

Percentages: per cent does not take a full point. Use pc only in headlines and % only in tables. In City page copy pc is acceptable. All percentages written in numbers, not in words: 5 per cent, never five per cent.

Note the difference between percentages and percentage points. If interest rates rise from 10 to 11 per cent, the increase is one percentage point or 10 per cent.

Metric units should not be abbreviated at first mention, except for mm for the calibre of weapons and the size of film. Litre should always be written in full, except in lists. The metric system is based on the metre (abbreviation is m), the litre (l) and the gram (g), and uses prefixes to denote that the unit has been divided or multiplied.

The prefixes are (with abbreviations): de ca (da) multiplied by 10, as in decagram meaning 10 grams; hecto or hect (h) multiplied by 100; kilo (k) multiplied by 1,000; mega (M) multiplied by a million. Deci (d) means tenth, centi (c) a hundredth, as in cl = hundredth of a litre; milli (m) a thousandth.

Common metric measures with abbreviations and equivalents include: millimetre (mm) 0.039 in, centimetre (cm) 0.394 in, metre (m) 1.094 yd, kilometre (km) 0.6214 mile, litre (1) 1.76 pints, kilogram (kg) 2.205lb.

When converting approximate distances treat the kilometre as five-eighths of a mile. Multiply centimetres by 0.4 to give inches, metres by 3.3 to give feet, sq metres by 1.2 to give sq yards, cubic metres by 1.31 to give cubic yards.

When in doubt consult the appendix in the Concise Oxford Dictionary.