Check-list to avoid vendor lock-in?

Question

Is there a set of industry-approved rules to avoid vendor lock-in?

I mean, something one can show to a manager, or other decision maker, that is easy to understand and easily verifiable.

• Are there any universally accepted set of rules, a checklist or set of conditions that helps detect and prevent vendor lock-in in an objective, measurable way?

• Have any of you warned a manager about the risk of vendor lock-in during the initial stages of a project?