Re: Several suggestions for image support

[Richard Stallman]

    In addition, the line-spacing property value may be negative, in which
    case the abs value is used as a total line height (so extra pixels are
    optionally inserted after the line to make its height the specified
    value, e.g.  the following are equivalent when the default face is used:

Wouldn't it be cleaner to distinguish this particular kind of
specification by something other than sign of the number?