I lost my most recent copy with the death of my laptop (thanks, Microsoft, for releasing untested software
).
But, usually, I have a spreadsheet fully up-to-date on firearms, optics, magazines, cases, and other accessories (like firearm-specific tools, slings, holsters, speed loaders, extra parts, etc).
I also keep photographs of each firearm that I care about (Taurus, Cobra, etc. is not worthy
). Left, right, serial number from about 24", serial number close-up, distinguishing features, and anything else that's important to document, should I have to file an insurance claim or police report.
In addition, I try to keep an updated serial number list in one (or both) of my brothers' safes. That way, if I lose
everything, there's still a list to be found (such as if there was a long, slow burning house fire, or a burglary that included my safes).
It has been a few years since one of them got an updated copy, though. Half of what I own has changed since then.
When I dig up an old backup copy of the spreadsheet and get it updated (it should be on a DVD and an external hard drive), I'm going to go with an online backup, as well.
The anti-virus company that I use offers 256-bit encrypted storage, and I'll save a copy there. ....No, I don't have fears of hackers or the government getting their hands on it and finding a way to use it against me.