This list started out as a file on my computer, just for me. I'd run across an interesting anthology, but I'd forget about it, or not remember until after the deadline had passed, or not remember the name of the book and not be able to find it again, so I started copying down relevant info, and listed them by due date. Then I figured that if the list was useful for me, it might be useful for others, so I might as well share it, and I started posting it.
Because of this origin, the listing is still based on what I'm interested in, with one or two grandfathered points, and one or two expansion points based on the interests of people I know who read my blogs. So frex., I started out subbing to semi-pro markets, as well as pro, and I still list (some of) them, even though I don't sub there myself anymore. And I started out only listing anthos in genres and subgenres I write in myself, but then I started listing Cthulu-based books for Charles, and I put in a Wu-Xia book for Winnie, etc., and finally opened it up to all fiction genres. So here's what I have now:
1. Pay rate. In order to be included on my listing, an anthology has to pay more than a penny per word, which is the rock-bottom semi-pro rate. For anthos that offer a flat payment, some significant percentage of the wordcount range has to work out to more than a penny per word. I don't write for peanut shells, and don't want to encourage my friends to do so either, so I don't list markets that pay peanut shells, or nothing at all. Note that if you don't state your pay rate on your guidelines, I'll assume you're paying nothing. I don't list royalty-split books, because with an anthology (especially by an unknown editor who can only afford to pay a royalty split) that usually means the editor sends everyone a check for a dollar-twelve every six months, which isn't worth anyone's time. I'll occasionally make an exception to the No Non-Paying Books rule for a charity anthology if I like the charity, but not often. This requirement is the number one reason why I've had to turn down requests to list.
If you have an opinion about this one, let me know.
3. Professionalism. If a book's guidelines or web site has what I consider red flags, I won't list it. If the editor falls all over themself to reassure everyone that they're Not Charging A Fee! to publish your story, that tells me they're a newbie at this, and coming from the wrong end of the business to boot; I'm not going to recommend writers submit to that book. If they want exclusive rights for an unreasonable amount of time, or subsidiary rights they don't need (seriously, movie rights? [eyeroll]) then I won't list that book. If the web site is riddled with copyedit errors, or the text is dark red on a black background, or the artwork is hideous, I'll assume that's what the finished anthology is going to look like too, and won't list the book.
4. General skeeviness. If, in my sole determination, the book sounds like it's going to be something I'd be ashamed to have my name in for reasons of skeeviness, then I won't list it. Frex., I ran across an anthology a while back whose primary theme seemed to be based on resurrecting the old pulp era trend of fetishizing, exoticizing or otherwise twisting non-European cultures for purposes of pointing and staring and maybe some sneering. The pay was good, but in the 21st century we really should be beyond that crap, so I didn't list it.
5. The hassle factor. Does the editor/publisher make it easy to find info about the anthology? If there's no one page that I can link to where all the info can be found (or maybe two if the book sounds otherwise stellar); if the editor/publisher didn't put up a page at all, just sent a note around to a few friends so they could post it on their blogs, but there's no official site for the anthology itself; if it's going to take too long to scrape together all the info from various sites and pages, I just won't bother. Seriously, if an editor/publisher can't get organized enough to put all the vital stats in one place and post it online, are they organized enough to put a book together, get it published, handle the marketing, and pay everyone on time? If you want folks to submit, get all your ducks in a row and then put them on one web/blog page.
6. Up to date info. This applies mainly to books that will remain open to submissions until they're filled, rather than having a firm deadline. I'll list an Until Filled book for a maximum of one year, at which point I'll take it off the list. I check the guidelines page each month to make sure it's still open before I post it in that month's listing. Note that I am not going to go on an Easter egg hunt through the editor or publisher's web site, looking for recent news. Everyone who bookmarks that page or publicizes the antho with a link to that page is going to be looking at that page. There should be an update posted prominently on that page if the book closes, or is cancelled, or acquires a firm deadline, or if anything else a writer needs to know changes, even if it's just a "NEW INFO!" note with a link to the page where the lengthier update is posted.
Taking all that into account, I'll list any anthology that looks interesting. I post about two months' worth at a time, based on deadline. So the post that goes up in August (somewhere between the 10th and 15th) will list books with deadlines between 31 August and 1 November. That limitation is to keep the list manageable. Most books with a firm deadline are on the list for two months, occasionally three depending on the exact due date. I figure two months is enough time for someone serious about subbing to write a story that fits.
If you're editing or publishing an anthology with open submissions, and you think your book will match my requirements, please do write me at angiepen at gmail dot com, with all the info and a link to your guidelines page, or even just a title and a link, and I'll be happy to help get the word out.
Addendum, August of 2016: My primary interest is in fiction. I've just posted my first listing for a non-fiction anthology of essays, though, so okay, that door is open. I'm not planning to go around looking for non-fiction projects, and writers really don't come to my blog looking for non-fiction calls. If you're editing a non-fiction anthology, though, and you want to get every tiny scrap of publicity, shoot me an e-mail and ask. If I think your project is interesting (and it meets all the other requirements above) I'll consider listing it. The bar is going to be pretty high for non-fiction, though, because I really don't want to get into searching out a whole new category of calls.