Saving passport information
According to this information on the ICAEW site, the things to be copied are fairly well defined. This is based in the UK.  See:

http://www.icaew.com/en/members/practice-resources/news/money-laundering-what-do-you-do-with-passports

Basically they say that identification: "For the purpose of due diligence evidence under the Money Laundering Regulations you may copy the personal details page only.

HM Stationery Office (HMSO) guidance also makes it clear that passport photocopies must be in black and white only, so that they cannot be mistaken for an actual passport page.

Furthermore, you are only allowed to copy the details page."

The HMSO (Her Majesty's Stationary Office) has similar details.

http://www.hmso.gov.uk/copyright/guidance/gn_20(old%20format).htm

So it seems that if you preserve a black and white copy of the personal details page, you are complying.  Of course, the one who makes the copy (or scan) should verify personally against the original passport that the bearer is indeed the person described.

The verification process may be more stringent depending on where you are.