Under 9.8.4.2 The Width Modifier, 6th para, search for "followed by the two digits of the minutes of the offset..".

And these six:
Under 8.3.1 fn:years-from-duration:
Under 8.3.2 fn:months-from-duration:
Under 8.3.3 fn:days-from-duration:
Under 8.3.4 fn:hours-from-duration:
Under 8.3.5 fn:minutes-from-duration:
Under 8.3.6 fn:seconds-from-duration:
Search for (same for all six): "If $arg is a negative duration then the result will be negative.."

For all of the above, the double dot should be a single dot.