This site was inspired by a discussion on a lichen listserv in which someone was looking for keys to lichens in understudied tropical areas. The idea for the archive began as simply a centralized source for lichen keys. However, reasons for an archive grew and now include the following (and probably more).

• Centralized location: It can be difficult and time consuming to find if a key for a particular group or location is available on the internet. Even the best of the search engines does not reveal all available keys. A single, well accepted web site known to most lichenologists could solve this problem.

• Stable location: Prior to the archive, my own key and several others have jumped around quite often as I and other people have moved or changed web-hosting services. Although it is impossible to guarantee complete stability (domain names do change), the archive has been located at a site less likely to change than someone's personal site. Furthermore, it is on the same server as another major lichenological website (the Recent Literature on Lichens site), thus if there is a change, they will hopefully move together.

• Reliable availability: Web pages, and keys frequently disappear. Keys found through search engines often no-longer exist. Pages with collected links to keys are difficult to maintain and frequently contain many broken links. A broken link may indicate that the key has been removed from the web by the author, but it may simply be from a temporary problem with a server. Therefore broken links are difficult to interpret, making it difficult to maintain a page of links to keys.

• Information preservation: One advantage to the internet is that it is easy to update information. However this can be a disadvantage as well. There are many reasons one might want to look back at an older version of a key, so the archive will maintain out-of-date keys through a clearly-marked "out-dated keys" page. I recently tried to use a web site that provides an up-to-date checklist but was told that I could not use it because it was not citable. The reason it was not citable is because there is no maintenance of older versions so the version I was using would be difficult to trace in the future. Instead, I had to use an older, published version. Admittedly, this archive has no 'quality control' so some of the keys here may not be reasonable for citing in scientific papers; however some of them are high quality and it would be beneficial to have them available for citation.

• Author encouragement: A centralized (and hopefully popular) key source will likely encourage more people to write keys for depositing in the archive. Authors need no website of their own, nor any HTML experience, only a word processor and a way to send the key to the currator.