…Is another man’s treasure. There are many different ways to document requirements when developing software. And there is a proliferation of requirements documents - MRD, PRD, SRS, FRS and design documents. Everyone has a perspective on what each document represents, and each person on the team has a unique perspective on what questions the document answers.

Article by Suzanne Robertson about how to approach writing requirements when you are under constraints that prevent you from completing them.  Good article, very stimulating discussion in the comments.

Article provides an overview of twelve rules for writing good requirements. Each rule has its own page (linked from this one).

From the article (by Scott Ambler):

UML 2 activity diagrams are typically used for business process modeling, for modeling the logic captured by a single  use case or usage scenario, or for modeling the detailed logic of a  business rule.  Although UML activity diagrams could potentially model the internal logic of a complex operation it would be far better to simply rewrite the operation so that it is simple enough that you don’t require an activity diagram. In many ways UML activity diagrams are the object-oriented equivalent of  flow charts and  data flow diagrams (DFDs) from structured development. 

High level overview of the processes that make up the bulk of requirements management work.

By writing better requirements

rather a database than an article. useful, however!

The Business Analysts Handbook has been launched by myself and a handful of friends and colleagues. From it's homepage; "This is a wiki for busness analysts to post thir knowledge. It is designed to be an evolving repository of knowledge for and about business analysts, or BAs." This site can be viewed as a business analysts body of knowledge, although rather that a formal and rigidly version controlled document such as PMIs PMBOK (or the proposed BABOK) my hope is that the wiki format will enable a broader contribution from practitioners and be a (cliché warning) live document, that evolves as the knowledge base grows.

Identifies the assumptions most commonly made by business analysts.  Also provides high-level steps for how to avoid those assumptions

This article is an informed and wide ranging history of the profession/role of the business analyst.  Written by a developer for developers to help understand the role and how to work with them.