Repeater databases always have, and always will, struggle with accuracy. It's the very nature of dealing with repeaters. They can be operational one minute and not the next. Power outages, hardware failures, site issues, etc., can all impact the operability of a repeater. Paper-based repeater directories are out of date the moment they are printed.
Electronic directories allow for instant updates of the directory. The power of the Internet can bring the data to anyone with a connection. Modern web design also allows for notifying interested persons about updates to a repeater's status the moment it is reported.
“Reported” is the operative word.
There is no requirement for any repeater owner to report the existence of their repeater to anyone. Not the FCC. Not a coordination council. It is certainly encouraged to report a repeater to the coordination group so that there is some standing if an interference claim is made. However, it is possible that someone can hold a coordination on a repeater that is non-functional or does not even exist.
We have not seen a repeater council track the current operational status of a repeater publicly. We have heard that some councils will respond to reports that a repeater is not functioning and require the repeater owner to commit to making the repeater functional again or risk having their coordination revoked. Only the most highly-motivated coordinators check repeaters for operability. We have seen this to be the exception and not the rule. Furthermore, some coordination groups are hesitant to post repeater data online or have no web presence at all. Some seek to gain revenue from their data.
Keeping the data private is of no value to the amateur radio community. We blame this practice on the ARRL, who would purchase repeater listings from coordination entities to publish in their own directory, which they sold. Repeater listings became a revenue stream for the ARRL, coordination councils, and others. A coordination council's decision to post data online only dilutes the profit that might be made by someone selling repeater data. As selling the data became a revenue stream for coordination groups who would sell for a dollar amount per listing, listing “paper”, or non-functional, repeaters only resulted in more profit.
With a fragmented system of coordination councils across the country (and world), sketchy data, and profiteering from the data itself, only made finding a good source of data very tough. The Internet tried to fix this as Hams all over the country would post repeater lists on the web or groups and individuals posting about their repeater(s).
Nwham.com was just one of these “fragmented” web sites. It started out as one Ham's personal list of repeaters programmed into the memories of his mobile and HT radios back in 2006. Then it expanded to repeaters that he might use when traveling to neighboring states. The web site name was changed to Repeaterbook.com and began to spread across North America, including Canada. As the area grew and the number of repeaters grew, modules were built to allow visitors to the site to add data. Admins were selected in areas to curate the data.