The reader is a customer. The documentation (strictly, the information in the documentation) is the product. If the product is not up to standard, you lose your customer: your documents go unread.

At a minimum, documentation should be:

Short. Literacy levels are low; and people are in a hurry. For many readers the practical limit is about one page: any more than that and it's easier to go and ask someone.

Simple. Most documentation is instruction: who does what. Narrative prose doesn't work. Hardly anyone can write it; no-one will read it.

Consistent. The terminology and style of the documents must be rigorously consistent. The language should match your forms and other paperwork, and your site signage.

Accessible. Literacy is not only the ability to understand a page of writing; your reader must also be able to find the page (bearing in mind that 30 percent of adults can't use the Yellow Pages).

Drivers licence: circle expiry date

Map: locate intersection

Deposit slip: enter cheque details

Yellow Pages: find phone number

Deposit slip: enter cash details

Pay slip: read gross pay to date

Yellow pages: find heading

Paint chart: identify use

Charge account: write cheque

Job application: complete past details

Paint chart: select product

Medicine label: correct dosage for child

Based on Wickert, R. No Single Measure: A Survey of Australian Adult Literacy. Commonwealth Department of Employment, Education and Training, Canberra 1989.