# - If .HP breaks .SS, a line is broken after the next input line.
# - If .RS/RE/nf/fi breaks .SS, the next input line becomes bold.
# - .UR does not break .SS.
# - If .HP breaks .SS, a line is broken after the next input line.
# - If .RS/RE/nf/fi breaks .SS, the next input line becomes bold.
# - .UR does not break .SS.