The PDF link Clyde mentioned is our documentation for the REST API right now. The developer site presented it differently but all the information is in there.
We're in the process of making a wiki for the REST API similar to our Automation Script documentation https://ibm-maximo-dev.github.io/maximo-autoscript-documentation/. We're hoping to make the new REST API wiki public around the 8.11 release timeline in September. The goal is to encompass what's in the PDF, add in newer functionality that may not have been documented in the PDF, and for the first time starting to document some of the business logic examples. Our REST API documentation has always focused on the technical capability (how do I search, how do I handle pagination, etc.) but when it comes to business logic questions (how do I move an asset from location A to location B, how do I create a follow up WO, etc.), it's been up to the customer to know how to do it. We'll obviously only be able to cover a subset of what's possible but as questions come up with "how do I do X", we think it'd be helpful to publicize for everyone to benefit from.