I was looking at cookbooks and saw this tag on several....Illegal item per PBS Rules - less than 50 pgs w/no ISBN - no credit will be given

What does this mean?  If they are "illegal" (I am assuming they should be unpostable) how are members able to post them?  Who put this tag on these books?  Members or TPTB?

Members tag books.

Anything with an ISBN can be posted, even if it's not technically legal on PBS.  Comic books aren't legal to be traded here, but they have ISBN's.  

Actually, I think comic books have ISSNs.  "Illegal" is probably a poor choice of words--they may be against PBS rules, but there are no laws being broken.

Members put the tags on the listings. PBS gets its database from an outside source, so it includes many things that have ISBNs but cannot be swapped here.

From the Help Center:

Not allowed:

• Anything that is not a book (this includes calendars, coloring books, blank journals)
• Anything that contains advertising (such as single-issue comic books or comic book digests or magazines)
• Advance Reader Copies* (also known as ARC s, Review Copies or Uncorrected Proofs--these are not the final versions of books)
• CD-ROM books/e-books (books that must be read on a computer)
• Burned copies of audio books
• Xerox or otherwise unoriginal copies of books
• Electronic media of any kind
• Unbound pages
• Music recordings, spoken-word recordings (these can be swapped as accompaniments to a bound book *for 1 credit for the set*, or at SwapaCD if they are in the database there. These are not "audio books," which are books read aloud by a narrator).
• Items of fewer than 50 pages (leaflets or pamphlets or booklets**) without ISBNs, or whose ISBNs are not included in our database (other members complain at spending a credit for these)
• Brochures/Promotional "first chapters" of books - these are not complete books, even if they have an ISBN
• Books that originally had accompanying media material, if the accompanying media are not included.
• Books that require supplementary non-media materials to be useful (non-media materials cannot be sent by MediaMail, and original non-media materials cannot be expected to be included with a used book)
• Pornography (sex manuals and erotica are allowed, hardcore pornography is not allowed)
• Supplementary media alone (without the book they originally accompanied)
• Audio language courses without accompanying bound book.  (if audio tapes/CDs ARE accompanied by a book they are considered a bound book with accompanying media, and swap for 1 credit. They are not "audio books," which are books read aloud by a narrator.)
• Books with water damage, or damage from any liquid
• Books with writing or highlighting (see the exception for textbooks/cookbooks/travel guides described in Book Condition Criteria for 'Swappability' at PBS)

*ARCs may be swapped "unofficially" in the Book Bazaar Discussion Forums.  They may not be posted to a PBS Bookshelf.

**A leaflet/pamphlet is an item with fewer than 20 pages; a booklet is an item with between 20 and 50 pages that is not a children's book. Children's books often have less than 50 pages and are not considered booklets just because of their short pagelength.

Please note: if you post an inappropriate item for swapping, it may be removed from the database as an automatic action without notice; if it has been requested from you before that happens, you will not get credit for sending it.  Also, If you request a disallowed item, you do so at your own risk.

At the moment there are 422 coloring books posted on PBS.  They are not allowed and yet people post them.  You can order them if you wish, but again it is against the rules.

I noticed someone has tagged some with illegal and some with not allowed.  

To answer your question, TPTB don't Tag things. Member's add Tags. Many of those types of Tags will be done by Data Editor team members and Tour Guides that try to do a little "clean up" on the system and encourage people to not swap things that are against the site's rules.

Per Cathy's post, a cookbook (or any book) of less than 50 pages is considered a pamphlet and not postable per PBS guidelines. 

Like coloring books tho, pamphlets are sometimes posted here.  Just be aware that the listing is for a small recipe booklet not a full size cookbook.  And if you choose to participate in such a swap...well, if there are any problems with the transaction TPTB will probably not intervene.

"Per Cathy's post, a cookbook (or any book) of less than 50 pages is considered a pamphlet and not postable per PBS guidelines. "

This is not correct. The rules on page length are

• Items of fewer than 50 pages (leaflets or pamphlets or booklets**) without ISBNs, or whose ISBNs are not included in our database (other members complain at spending a credit for these) are not allowed
• Leaflets/pamphlets are items with fewer than 20 pages and are not allowed
• ** Booklets are items with between 20 and 50 pages that are not children's books. Children's books often have less than 50 pages and are not considered booklets just because of their short pagelength and are allowed
• Books less than 50 pages with ISBNs in the PBS database are allowed

THANKS!!! They were probably cook booklets with a certain number of pages (50 or less), that are unpostable.