What is the ORCID identifier? How do I register?
https://orcid.org/

NLM Style Guide for Authors, Editors and Publishers
https://www.ncbi.nlm.nih.gov/books/NBK7256/

What is Mendeley?
Mendeley is a web and desktop application, owned by Elsevier. It is a free reference manager that allows you to store, organize, annotate, share, cite references and research data online.

What is Zotero?
Zotero is a free software program for bibliographic reference management that allows users to collect, manage and cite research of all kinds. It imports data directly from the web pages currently viewed.

If you need more information about Mendeley and Zotero you can consult the following link https://www.bvsodon.org.uy/que-son-los-manejadores-bibliograficos/