Industrial use of program assertions for the purpose of Run-time Assertion Checking (RAC) is becoming commonplace. A likely next step in the use of assertions is Extended Static Checking (ESC), an area of active research that promises added benefits to industry. Unfortunately, RAC and ESC tools are not consistent in their interpretation of assertions containing undefined terms. In this paper, we report on the results of a survey in which we asked industrial developers what logical semantics they want program assertions to have, and whether consistency across tools is important. Survey results indicate that developers are in favor of a semantics for assertions that is compatible with their current use in RAC.