Definition(s)
Written
The instructions need not be on paper to be ‘written’. They can be computer generated, for example, so long as they are capable of being printed out or read (eg on a display screen or electronic sign board) and understood by those who need to see them.
Source: A Guide to the Offshore Installations and Pipelines Works (Management and Administration) Regulations 1995, Guidance on Regulations (UK HSE L70), Second Edition, 2002. Regulatory Guidance