Both Arabic and Roman numerals have the POS-tag XY
(which in the HiNTs tagset stands for a ‘non-word’):
(NP-OB1 (NP-POS (DDARTA des) (NA volkes) (PP (APPR von) (NP (NE Sirien)))) (XY 100.000) ← Arabic numeral )
(FRAG (FM Dominica) (XY iiij) ← Roman numeral (FM post) (FM aduentum) )
This contrasts with numbers which are spelled out. These are tagged CARD*
:
(NP-TMP (CARDA dre) ← spelled out number (NA iar) )