(what the &^%% happened to the reply compose window?!)
I completely agree with smacca. For purposes of gifted milestones - well, it just shows how problematic those are, really. I don't have my copy in front of me, but I remember Miraca Gross commenting on this problem and saying that she used a particularly stringent definition of reading so that by other authors' definitions her children might have been reading much earlier. I forget exactly what her definition was, so I may be doing her an injustice, but IIRR it was of the order of "can read at least 5 words without pictorial or other clues". I remember being struck by how astonishingly unstringent her definition was, anyway - it placed my DS's "can read" milestone way before seems reasonable (like, before he could talk, before his second birthday). I also felt obliged to notice that we have ample evidence that babies can be taught to recognise symbols such as words with sufficient ease that any parent who wanted to ensure that their child "could read" before 6 months could surely do so with only moderate effort, if that's the definition!