A tag is a label that classifies eprints in a non-hierarchical manner. Using the tags makes it easier to find articles with specific features.

• journal article: An article published in a journal.
• review article: An article that summarizes the work of a particular sub-field rather than reports on new results.
• expository article: A survery on a well specified topic written at a level accessible to non-experts.
• conference paper: A paper published in the context of an academic conference.
• commentary: An article expressing the authors' view about a particular issue.
• book review: A form of literary criticism in which a book is analyzed based on content, style, and merit.
• book chapter: A individual chapter in an edited book or collection.
• monograph: A specialist work of writing on a single subject or an aspect of a subject.
• textbook: A manual of instruction in a branch of study.
• dissertation: A document submitted in support of candidature for an academic degree, also known as a thesis.
• research tool: A software package or module that helps conducting research.
• manual: A technical document intended to give assistance to people using a particular system, also known as a user guide.
• lecture notes: A record of the lecture content in an accessible way.
• problem book: A textbook in which the material is organized as a series of problems, each with a complete solution given.
• popular level: An article accessible to the mass public without specialized knowledge.
• undergraduate level: An article accessible to undergraduate students.
• graduate level: An article accessible to graduate students and nonspecialist researchers.
• famous paper: A paper whose number of citations is among the top 1% in the field.
• featured article: An article with at least 100 ratings and an average rating score greater than or equal to 4.
• highlighted article: An article with at least 100 ratings and an average rating score greater than or equal to 3.
• kaleidoscope: An article containing aesthetically attractive images like the journal cover arts.
• github project: An article which has a public repository on GitHub.