I have self-published a paperback and Kindle version of a book on Amazon KDP. For the paperback, I got a free ISBN from KDP. My question is, can I also publish a free e-book version somewhere else, like Smashwords? Note that I did not enroll in KDP Select.
As stated on a similar question on Quora, you can publish in multiple places if you publish with KDP.
If, however, you publish with KDP Select, as stated in the terms and conditions, you cannot publish elsewhere:
When you include a Digital Book in KDP Select, you give us the exclusive right to sell and distribute your Digital Book in digital format while your book is in KDP Select. During this period of exclusivity, you cannot sell or distribute, or give anyone else the right to sell or distribute, your Digital Book (or a book that is substantially similar), in digital format in any territory where you have rights.
This exclusivity appears to be for 90 days, unless you renew, in which case it may last longer.