To make sure that your code will keep working as expected in the future, do not use obsolete functions:

No longer supported by main vendors
Support to be removed by main vendors

Noncompliant Code Example

.mybox {
  font-size: min(10px, 3em); /* Noncompliant */
  font-size: max(10px, 3em); /* Noncompliant */
}

Obsolete Functions

`alpha`	`basicimage`	`blendtrans`
`chroma`	`color-stop`	`compositor`
`emboss`	`engrave`	`expression`
`fliph`	`flipv`	`from`
`glow`	`gradient`	`gray`
`icmfilter`	`light`	`mask-filter`
`max`	`min`	`motionblur`
`progid:dximagetransform.microsoft.alpha`	`progid:dximagetransform.microsoft.alphaimageloader`	`progid:dximagetransform.microsoft.barn`
`progid:dximagetransform.microsoft.basicimage`	`progid:dximagetransform.microsoft.blendtrans`	`progid:dximagetransform.microsoft.blinds`
`progid:dximagetransform.microsoft.blur`	`progid:dximagetransform.microsoft.checkerboard`	`progid:dximagetransform.microsoft.chroma`
`progid:dximagetransform.microsoft.compositor`	`progid:dximagetransform.microsoft.dropshadow`	`progid:dximagetransform.microsoft.emboss`
`progid:dximagetransform.microsoft.engrave`	`progid:dximagetransform.microsoft.fade`	`progid:dximagetransform.microsoft.fliph`
`progid:dximagetransform.microsoft.flipv`	`progid:dximagetransform.microsoft.glow`	`progid:dximagetransform.microsoft.gradient`
`progid:dximagetransform.microsoft.gradientwipe`	`progid:dximagetransform.microsoft.gray`	`progid:dximagetransform.microsoft.icmfilter`
`progid:dximagetransform.microsoft.inset`	`progid:dximagetransform.microsoft.invert`	`progid:dximagetransform.microsoft.iris`
`progid:dximagetransform.microsoft.light`	`progid:dximagetransform.microsoft.maskfilter`	`progid:dximagetransform.microsoft.matrix`
`progid:dximagetransform.microsoft.motionblur`	`progid:dximagetransform.microsoft.pixelate`	`progid:dximagetransform.microsoft.radialwipe`
`progid:dximagetransform.microsoft.randombars`	`progid:dximagetransform.microsoft.randomdissolve`	`progid:dximagetransform.microsoft.redirect`
`progid:dximagetransform.microsoft.revealtrans`	`progid:dximagetransform.microsoft.shadow`	`progid:dximagetransform.microsoft.side`
`progid:dximagetransform.microsoft.spiral`	`progid:dximagetransform.microsoft.stretch`	`progid:dximagetransform.microsoft.strips`
`progid:dximagetransform.microsoft.wave`	`progid:dximagetransform.microsoft.wheel`	`progid:dximagetransform.microsoft.xray`
`progid:dximagetransform.microsoft.zigzag`	`redirect`	`revealtrans`
`shadow`	`to`	`toggle`
`wave`	`xray`