Code conventions are important to software developers for a number of reasons:
80% of the lifetime cost of a piece of software goes to maintenance.
Hardly any software is maintained for its whole life by the original author.
Code conventions improve the readability of the software, allowing engineers to understand new code more quickly and thoroughly.
If you ship your source code as a product, you need to make sure it is as well packaged and clean as any other product you create.
These same reasons apply to build engineers maintaining Ant build files.
Keep in mind that these are guidelines, not hard and fast rules. The ultimate goal is readability and maintainability.
These guidelines have been compiled from the Ant user guide, Sun's Java coding style guidelines, example build files from various Jakarta applications, and e-mail messages on the Ant mailing lists.