"Grey rollout log" could refer to a document or record related to the rollout process of a project, product, or system. In this context, "rollout" typically means the deployment or introduction of something new. The term "grey" might signify that the document is in a draft or preliminary stage, or it could simply refer to the color of the document.

In practical terms, a grey rollout log might include details such as:

1. Timeline: Dates and times of each stage of the rollout process.
2. Activities: Description of activities undertaken during the rollout, such as testing, training, and deployment.
3. Issues and Resolutions: Any problems encountered during the rollout and how they were addressed.
4. Stakeholders: Information about the individuals or teams involved in the rollout process.
5. Feedback: Comments or feedback received during or after the rollout, which could be used for future improvements.

The term could also be interpreted differently depending on the specific context in which it's used, so additional information might be needed to provide a more accurate explanation.