@mattly also searchability, availability offline/away from the office, usability in a datacentre environment (noisy, busy, potentially physically hazardous if some muppet has the floortiles up without warning again).

my basic rule of documentation is:
can you print it out, stick it in a folder and refer to it during a full power-outage?
you don't actually need to do that for all the docs but at a basic level it sets the expectation that you might need it in less than ideal circumstances