Anchoring is the process of creating and maintaining the correspondence between symbols and percepts that refer to the same physical objects. Although this process must necessarily be present in any symbolic reasoning system embedded in a physical environment (e.g., an autonomous robot), the systematic study of anchoring as a clearly separated problem is just in its initial phase. In this paper we focus on the use of symbols in actions and plans and the consequences this has for anchoring. In particular we introduce action properties and partial matching of objects descriptions. We also consider the use of indefinite references in the context of action. The use of our formalism is exemplified in a mobile robotic domain.