programmatically determined
determined by software from data provided in a user-agent-supported manner such that the user agents can extract and present this information to users <del>in different modalities</del>[Some user agents may present in one and only one modality. Plurality is not an essential part of the definition][I am not sure I fully understand this concept of programmatically determined]
The working group felt that the use of "in different modalities" here is important since it is meant that different user agents and assistive technologies (whose users may require that information be presented in different modalities) can access and present the information. In other words, if information could only be presented in a single modality, that information could not be programmatically determined.