The text on <input type=range> at:
http://www.whatwg.org/specs/web-apps/current-work/multipage/states-of-the-type-attribute.html#range-state-%28type=range%29
says:
The step scale factor is 1. The default step is 1 (allowing only
integers, unless the min attribute has a non-integer value).
I found the words "allowing only integers" to be confusing. I initially read it
to mean that "step" is only allowed integer values unless the "min" attribute is
a number with a fractional part. Talking it over with dbaron we believe it is
probably just a parenthetical observation that if the "min" attribute's value is
an integer and the default value of 1 for "step" is being used, then the input's
value can only have integer values. (This is unclear because the input's value
isn't otherwise mentioned in the sentence.)
Jonathan
