What Compliances and legal Considerations do you keep in mind when running text messaging campaigns, especially in regulated industries or regions?

When running text messaging campaigns, especially in regulated industries or regions, what specific compliance and legal considerations do you diligently keep in mind? Please provide detailed insights into the measures you undertake to ensure compliance, any specific regulations you adhere to, and the challenges you face in navigating the legal landscape. Additionally, share any best practices or resources you have found helpful in maintaining compliant text messaging campaigns in highly regulated environments.