What's the reason for job titles ending a the letter 'D'?

Clay has a job title mapping feature that helps categorize job titles into predefined personas. The system uses keywords to automatically map job titles to specific personas to streamline lead segmentation and targeting processes. However, there's no indication in the available sources that job titles specifically end with the letter 'D' - this appears to be a misunderstanding. Source: Map Job Title to Persona with Clay