While the start
attribute in HTML 4 is indeed deprecated, looking at the HTML 5 docs, I see:
The start
attribute, if present, must be a valid integer giving the ordinal value of the first list item.
If the start
attribute is present, user agents must parse it as an integer, in order to determine the attribute's value. The default value, used if the attribute is missing or if the value cannot be converted to a number according to the referenced algorithm, is 1 if the element has no reversed
attribute, and is the number of child li
elements otherwise.
The first item in the list has the ordinal value given by the ol
element's start attribute, unless that li
element has a value attribute with a value that can be successfully parsed, in which case it has the ordinal value given by that value attribute.
which tells me I am safe using start
with ol
and value
with li
elements.