Pat Naughtin asked in ISMA 11173:
>BTW do you know if it is good SI practice to use an SI symbol as part of a
>sentence as you have here as 'in a ha'. I have always written the unit name
>in full under these circumstances and reserved the unit symbol to use in
>conjunction with a number. However, I have no idea why I do this and I can't
>supply a reference.
CAN/CSA-234.1-89 says:
"3,6,3 When a unit symbol is used to express a quantity, the associated
numerical value shall be expressed as a numeral. When no numeral is
involoed, the unit should be spelled out. In tachnical writing, the form
preferred is the numeral with the unit symbol.
"Example: The volume of concrete required is 16 m3, or sixteen cubic
metres.* Concrete is sold by the cubic metre (not by the m3).
"*The form "16 cubic metres" is not recommended for technical use but may
be preferable for better communication.*"
NIST Special Publication 811, 1995 Edition, says:
"7.8 Unacceptability of stand-alone unit symbols
"Symbols for units are never used without numerical values or
quantity symbols (they are not abbreviati0ons).
"Examples:
"there are 10^6 mm in 1 km *but not:* there are many mm in a km
"it is sold by the cubic meter *but not* it is sold by the m3"
Joseph B. Reid
17 Glebe Road West
Toronto M5P 1C8 Tel. 416 486-6071
