Input:
<span style="letter-spacing: 3pt">3pt</span>

Output:
NSParagraphStyle:
Alignment 4
    LineSpacing: 0
    ParagraphSpacing: 0
    ParagraphSpacingBefore: 0
    HeadIndent: 0
    TailIndent: 0
    FirstLineHeadIndent: 0
    LineHeight: 0/0
    LineHeightMultiple: 0
    LineBreakMode: 0
    Tabs: ()
    DefaultTabInterval: 36
    Blocks: (null)
    Lists: (null)
    BaseWritingDirection: 0
    HyphenationFactor: 0
    TighteningFactor: 0.05
    HeaderLevel: 0
[3pt]
    NSFont: Times-Roman 16.00 pt.
    NSKern: 4pt
[ ]
    NSFont: Times-Roman 16.00 pt.