In [u]abbreviations[/u] and Roman numerals, the effect of a double capitalization indicator extends to all the letters that follow, but a symbol other than a letter terminates its effect. In abbreviations, the double cap would end at a hyphen. Rule III sec. 22b
This rule does not apply to hyphenated compound words. The effectiveness of the double cap would extend through the hyphen. Could you cite the reference that says "a symbol other than a letter or a hyphen terminates its effect"?