[NTG-context] \setupheadnumber and zero

Hello, can a section head be generated with the number 0 (or less)? Sometimes I need to prepend a section while keeping existing section head numbers... Example: ---- \starttext \setupheadnumber[chapter][-1] \chapter{Ch0} % Getting "Ch0" instead of "0. Ch0"? \chapter{Ch1} \stoptext ---- Here, "0. Ch0" is not generated, the zero is not displayed; why? Best regards, Lukas -- Ing. Lukáš Procházka | mailto:LPr@pontex.cz Pontex s. r. o. | mailto:pontex@pontex.cz | http://www.pontex.cz Bezová 1658 147 14 Praha 4 Tel: +420 241 096 751 Fax: +420 244 461 038