# Access rules

Access rules are Ant patterns defined on build classpath entries that tells the compiler to signal the use of types matching the patterns.

- Non-accessible rules define types that must not be referenced.
- Discouraged rules define types that should not be referenced.
- Accessible rules define types that can be referenced.

Java builder
Exclusion and inclusion filters

Adding a JAR file to the build path
Adding a library folder to the build path
Building a Java program
Viewing and editing a project's build path
Working with build paths

Java Build Path properties