Unitless CSS Lengths

Properties that may be given a <length> value in CSS 2 are:

background-position	[ [<percentage> | <length> ]{1,2} | [ [top | center | bottom] || [left | center | right] ] ] | inherit
border-spacing	<length> <length>? | inherit
bottom	<length> | <percentage> | auto | inherit
font-size	<absolute-size> | <relative-size> | <length> | <percentage> | inherit
height	<length> | <percentage> | auto | inherit
left	<length> | <percentage> | auto | inherit
letter-spacing	normal | <length> | inherit
line-height	normal | <number> | <length> | <percentage> | inherit
marker-offset	<length> | auto | inherit
max-height	<length> | <percentage> | none | inherit
max-width	<length> | <percentage> | none | inherit
min-height	<length> | <percentage> | inherit
min-width	<length> | <percentage> | inherit
right	<length> | <percentage> | auto | inherit
size	<length>{1,2} | auto | portrait | landscape | inherit
text-indent	<length> | <percentage> | inherit
text-shadow	none | [<color> || <length> <length> <length>? ,]* [<color> || <length> <length> <length>?] | inherit
top	<length> | <percentage> | auto | inherit
vertical-align	baseline | sub | super | top | text-top | middle | bottom | text-bottom | <percentage> | <length> | inherit
width	<length> | <percentage> | auto | inherit
word-spacing	normal | <length> | inherit