One sees on web sites and Agent Query and such the phrase "actively seeking new clients." Does this necessarily mean they are truly interested in queries from the previously unpublished? I've noticed some sites specify "new writers". Some don't. Or is it an invitation to established writers unhappy with their present circumstances, whose agent has fled the country, died and gone to heaven, moved back into editing, turned pathological or whatever? An obvious industry understanding that in our bounding enthusiasm, we fail to comprehend.
Interpreting even seemingly plain language can be a bitch when we lack the insider context.
The funny thing here is agents also parse out what will draw the clients we want and discourage the hobbyists. By hobbyist I do NOT mean unpublished. I mean someone who is writing for fun and not investing much time or effort in learning about the biz. (Reading this blog of course removes you from that category by royal decree from the Queen of All That Is Snark).
It's been awhile since I listed myself with the Writers Market and Agent Query and their ilk. Truthfully I send answers to them if they email me, or if my contact info changes, but otherwise I don't really think about it--which leads to info being out of date I'm sure. As I recall they give you choices to indicate what you want to receive and "actively seeking new clients" is one, and "only by referral" is another. There isn’t a place to write something like “new but only if you’ve read Miss Snark’s blog faithfully and know what you are doing sort of”.
The writers who have shed their old agents usually come to me by referral. They ask their writer friends, or their editors for recommendations.
If you are a new unpublished writer, query everyone. Even if they say they only take people by referral. You have nothing to lose. If they write back and say you're a nitwit, that's the cost of being bold. You'll need to develop a tough hide for scathing reviews from Dale Peck when your novel is published, and loathsome reviews on Amazon from people who are envious, so you might as well start now. And if you are fabulous, trust me, writing trumps everything including “no newbies” warning signs in Agent Query.