Rules - CSSLint/csslint GitHub Wiki
Parsing errors should be fixed
The most important rule, as far as CSS Lint is concerned, is to ensure there are no parsing errors in the CSS. Parsing errors usually mean you mistyped a character and caused the code to become invalid CSS. These errors may cause the browser to drop a property or an entire rule. Parsing errors are always presented as errors by CSSLint, the most important issues to fix.
Possible Errors
The following rules point out potential errors in your CSS.
box-model: Beware of box model sizedisplay-property-grouping: Require properties appropriate for displayduplicate-properties: Disallow duplicate propertiesempty-rules: Disallow empty rulesknown-properties: Require use of known properties
Compatibility
The following rules flag for compatibility problems across browsers and browser settings.
adjoining-classes: Disallow adjoining classesbox-sizing: Disallow box-sizingcompatible-vendor-prefixes: Require compatible vendor prefixesgradients: Require all gradient definitionstext-indent: Disallow negative text-indentvendor-prefix: Require standard property with vendor prefixfallback-colors: Require fallback colorsstar-property-hack: Disallow star hackunderscore-property-hack: Disallow underscore hackbulletproof-font-face: Bulletproof font-face (new in v0.9.10)
Performance
The following rules are aimed at improving CSS performance, including runtime performance and overall code size.
font-faces: Don't use too many web fontsimport: Disallow @importregex-selectors: Disallow selectors that look like regular expressionsuniversal-selector: Disallow universal selectorunqualified-attributes: Disallow unqualified attribute selectorszero-units: Disallow units for zero valuesoverqualified-elements: Disallow overqualified elementsshorthand: Require shorthand propertiesduplicate-background-images: Disallow duplicate background images
Maintainability & Duplication
These rules help to ensure your code is readable and maintainable by others.
floats: Disallow too many floatsfont-sizes: Don't use too many font-size declarationsids: Disallow IDs in selectorsimportant: Disallow !importantorder-alphabetical: Disallow non alphabetical
Accessibility
These rules are designed to pick out possible accessibility issues.
outline-none: Disallow outline:none
OOCSS
These rules are based on the principles of OOCSS.
qualified-headings: Disallow qualified headingsunique-headings: Headings should only be defined once