We received some questions from a chartered museum about weeding from the museum's internal research library:
Put your sneakers on. These questions require us to jump through several analytical hoops.
First, a library that is part of a chartered museum or historical society in the state of New York, when weeding materials, must figure out which, if any, of the materials within the library are part of the museum's official collection, and thus controlled by the museum's "collection management policy."
Most museums and historical societies maintain good records of this, and it's a yes-or-no question, so this first hoop is fairly simple.
With collection status determined, any materials within the library that were "accessioned" (brought into the museum's official collection) under the collection management policy must also be "de-accessioned" per that policy, before they can be weeded from the library's collection and thrown out, donated or sold.
Any materials that were not accessioned into the museum's official collection are still assets of the chartered entity, but do not have to go through the de-accession ritual prior to what comes next.
Next, the museum or historical society must determine if there are any conditions or restrictions on the materials, such as a donor agreement, a grant, or other contractual terms. If there are any restrictions, those must be addressed.
Next is to confirm ownership. If the museum doesn't have a clear record of how the materials were acquired (either by purchase or donation), or if they were loaned to the museum and never picked up, the museum must follow the procedure in Education Law 233-aa to assert its ownership before it can consider any removal.
After doing what's needed to establish the materials' status, the museum can then--as governed by its own charter, bylaws, and policies--either 1) donate the materials to another charitable organization (transfer for free to an individual or for-profit organization could cause problems), or 2) sell them for fair market value to any organization it wishes (profit, non-profit, or individual).
Contingent Hoop 6 (the "de-accession hoop")
Of course, sale or donation of any items that started out in the collection will be governed by the factors in the regulations governing de-accession (8 NYCRR 3.27). This consideration was already raised in Hoops 1 and 2, but is so critical, it is worth mentioning again.
Contingent Hoop 7 (the "233-aa contingency hoop")
If the materials were "undocumented property" or "unclaimed property" under 233-aa, and the materials are to be sold, there is an extra consideration: any proceeds derived from the sale of the materials can only be use for "the acquisition of property for the museum’s collection or for the preservation, protection, and care of the collection and shall not be used to defray ongoing operating expenses of the museum."
And with all those hoops complete, there you have it: a full cardio workout, based on assessing a museum's library's property's status under the law.
I hope this analysis and advice are helpful (and good exercise).
 A museum or historical society cannot operate a library with circulation to the public without provisions in its charter. However, a museum or historical society can operate an internal library for purposes of supporting the collection, and that's what we're talking about here. 8 NYCRR 3.27(f)(3).
 Which should follow the regulations set out in 8 NYCRR 3.27
 I have been told that most librarians do not have the same gut-wrenching aversion to the idea of throwing out books that I do. Typing "thrown out" actually made me wince.
 This is one of my favorite laws on the books, because it contains the magic formula for transforming an object of unknown origin, or an abandoned object, into the property of the museum. That said, in practice, it can be a bit of a pain, because the formula contains multiple steps and a publications requirement.
 The last question, thankfully, requires no hoops: "sale" could certainly include an auction, or any other legitimate method of transferring title for consideration (money, or assets in-kind).
 A sale for a nominal amount, or for less than fair market value, to a for-profit or individual can impact charitable and 501(c)(3) status.
 Since the library within the museum is not a chartered library, it does not have to follow the requirements of Education Law 226.6(b), requiring that materials be offered to a local charity or political subdivision.
 Could I sneak another apostrophe in there? How about: "museum's library's property's boxes' cardboard's strength?" Oh, yeah.