O’Reilly author Shelley Powers is a heavy user of Kindle’s “clipping” feature, and has run into an apparently undocumented clipping limit imposed by Amazon:
I tried to find information about the clipping limit in the Kindle TOS or User Guide, but nothing was covered. I also tried to find out if one can “delete” items from the existing clipping file, in order to replace with other clippings at a later time, but once the limit is reached, nothing associated with the book can be added to the clipping file, not even a highlighted sentence.
Shelley also notes that the clipping limit applies to DRM-free books as well, which definitely doesn’t make much sense.