-2. Compiles cleanly with no warnings when compiled with `-W -Wall -std=c99`
-3. Uses [Allman-style](https://en.wikipedia.org/wiki/Indent_style#Allman_style) code blocks & indentation
-4. Uses 2-character tabs and 2-character indentations
-5. Uses lower-case function and variable names
-6. Avoids the use of `!` and uses positive conditionals wherever possible (e.g., `if (foo == 0)` instead of `if (!foo)`, and `if (foo)` instead of `if (foo !=0)`)
+3. Compiles cleanly with no warnings when compiled with `-W -Wall -std=c99`
+4. Uses [Allman-style](https://en.wikipedia.org/wiki/Indent_style#Allman_style) code blocks & indentation
+5. Uses 2-spaces as indentation or a tab if it's required (for example: Makefiles)
+6. Uses lower-case function and variable names
+7. Avoids the use of `!` and uses positive conditionals wherever possible (e.g., `if (foo == 0)` instead of `if (!foo)`, and `if (foo)` instead of `if (foo !=0)`)
+8. Use code like array[index + 0] if you also need to do array[index + 1], to keep it aligned