> Like, if waterfall of a project can be done in 2 weeks, is it agile now?

Sure. The thing is, the waterfall guys would tell you it's impossible to do it in 2 weeks because you need to have written down everything first. "Thousands of pages" was the terms they used.

Agile guys would point you to the Agile manifesto which would lead you to "working code over documentation" and "people over process".

A 2 week period to go from initial spec to product in a user's hands to capture feedback and make changes from there is much closer to agile than to waterfall. In fact it's more or less exactly some older versions of Scrum (which didn't permit deviating from the planned sprint user stories midway through the sprint, instead changes influenced the subsequent sprint).

The DoD's 2167 standard from the late '80s mentions the following documentation that should be produced as part of the development process (section 6.2 and Appendix D):

- System/Segment Specification

- Software Development Plan

- Software Configuration Management Plan

- Software Quality Evaluation Plan

- Software Requirements Specification

- Interface Requirements Specification

- Software Standards and Procedures Manual

- Software Top Level Design Document

- Software Detailed Design Document

- Interface Design Document

- Data Base Design Document

- Software Product Specification

- Version Description Document

- Software Test Plan

- Software Test Description

- Software Test Procedure

- Software Test Report

- Computer Sytem Operator's Manual

- Software User's Manual

- Computer System Diagnostic Manual

- Software Programmer's Manual

- Firmware Support Manual

- Operational Concept Document

- Computer Resources Integrated Support Document

- Configuration Management Plan

- Engineering Change Proposal

- Specification Change Notice