1. Original (not derivative)
2. Opening documentation: Purpose, Author, Reference, Date, Version, Notes, etc. (edit Bareminimum.ino sketch for efficiency)
3. Formatted
4. Modularity: highly cohesive; loosely coupled
5. Hieracrchical Design (Scalable): highly-leveragd code, threaded from global/class constants and variables, ensures a robust response to changing project task size
6. Scope: priority for local variable declarations over global
7. Well-named, consistent, identifiers
8. Data types: memory sizes (byte, int, long, single, float, etc.), primitive vs composite (arrays, structs, etc.), all correctly initialized
9. Efficient
10. Application Specific: In this case: external interrupt
11. Well-documented throughout
12. Easy to read (no attempt to be cryptic aka, show off)
13. Keep statements lengths to the width of your IDE (JG)
14. Any others ?

Why Everyone Should Learn to Code