Crossley's Field Guide has an index of them, if you'd rather have it in book form. The guide is pretty useful as well. Wayne Patterson Shannon, MS Lee Co. On Monday, January 5, 2015 2:40 PM, JR Rigby <jr.rigby@xxxxxxxxx> wrote: Hi Jesse, These four letter codes are used by bird banders and often as shorthand among birders. They suffer from being easier to use than to decipher because most of them are constructed in a very regular and easy to remember way (but this often leads to use of incorrect codes where they deviate from the pattern... adding to confusion). The codes and their decoding are available here: http://www.birdpop.org/DownloadDocuments/Alpha_codes_tax.pdf Just use a simple ctrl-f search to find the common name or code of interest. There is also a recent and exhaustive set of commentary about usage of these codes by birders available on the ABA Blog: Rich Wright: http://blog.aba.org/2014/12/the-code.html Derek Lovitch: http://blog.aba.org/2014/12/open-mic-the-deal-with-alpha-codes-part-1.html Derek Lovitch Part II: http://blog.aba.org/2014/12/open-mic-the-deal-with-alpha-codes-part-2.html Hope that helps, JR Oxford On Mon, Jan 5, 2015 at 2:29 PM, Jesse Yancy <jlyancy@xxxxxxxxxxx> wrote: This might sound simplistic, but I’m often confused by the new abbreviations that are often used in this forum (TRKI for tropical kingbird, for instance) and I was wondering if there is some sort of guide to these or are they just ones birders use as shorthand. >Jesse Yancy >