2.1.23 [CSS-Level2-2009] Section 5.12.2, The :first-letter pseudo-element

V0020:

The specification states:

 These are the properties that apply to :first-letter pseudo-elements: font 
 properties, 'text-decoration', 'text-transform', 'letter-spacing', 'word-spacing' 
 (when appropriate), 'line-height', 'float', 'vertical-align' (only if 'float' is 
 'none'), margin properties, padding properties, border properties, color property, 
 background properties. UAs may apply other properties as well. To allow UAs to 
 render a typographically correct drop cap or initial cap, the UA may choose a line-
 height, width and height based on the shape of the letter, unlike for normal 
 elements. CSS3 is expected to have specific properties that apply to first-letter.

Quirks Mode and IE7 Mode (All Versions)

The float, letter-spacing, padding, and line-height properties are not supported.

IE7 Mode (All Versions)

The border property is applied to the bottom border; the bottom border is clipped at the content edge.

V0021:

The specification states:

 Punctuation (i.e, characters defined in Unicode [UNICODE] in the "open" (Ps), 
 "close" (Pe), "initial" (Pi). "final" (Pf) and "other" (Po) punctuation classes), 
 that precedes or follows the first letter should be included.

Quirks Mode and IE7 Mode (All Versions)

Punctuation characters defined in Unicode that precede or follow the first letter are not included.

V0022:

The specification states:

 Some languages may have specific rules about how to treat certain letter 
 combinations. In Dutch, for example, if the letter combination "ij" appears at the 
 beginning of a word, both letters should be considered within the :first-letter 
 pseudo-element.

All Document Modes (All Versions)

Letter combinations are not considered for the purpose of :first-letter pseudo-element matching.