Anyone in the world. Registering for an ORCID iD is free and requires only your name, an email address, and a password. Sign up here.
ORCID is designed to be interoperable with many other author identity systems such as Scopus’ Author ID or PubMed Central ID. In addition, publishers and funding organizations such as the NIH, NSF, and Wellcome Trust are using or planning to use ORCID iDs in their records to facilitate grant application and manuscript submission processes.
No. ORCID allows for any publication type, conference proceedings, and intellectual property (including patents, licenses, and registered copyright items). ORCID will also be including other forms of works like datasets and grant funding in the future.