Related Clues:

• Unwilling to bend
• To the letter
• Stern about the rules
• Like a martinet
• Inflexible about rules
• Observing exact rules
• Severe and unyielding
• Harsh and severe
• Rigid or exacting
• Stern and rigid
• Rigorous, uncompromising
• Severe, rigid
• Exacting, severe, rigid
• Severe, stern
• Rigidly accurate