Tagging systems exist that support tagging of resources, like, web pages, web links, videos, images and blogs. In web applications, use of tag facilitates categorization of related content and improves search within a resource, like, searching a blog or a page. During the development of web application, there is a need for eliciting the requirements for the tagging functionality in the web application. In this paper, we present a requirement checklist for tagging, from the viewpoint of incorporating the tagging functionality in a web application. A use-case based approach has been followed to identify the requirements for tagging. We see that the requirements for tagging vary, depending on the kind of permission provided to the user for the purposes of tagging. Also, there is a need to include resource-specific features. Accordingly, we categorize user requirements based on user-permissions for tagging, and also list the resource-specific features. Our checklist is beneficial both for the web application and the developer during the requirement specification process. During testing, the requirement checklist for tagging is useful for the validation and verification purposes.