The document type definition (DTD) looks like this:
<!ELEMENT ORDER (HEADER+)>
<!ELEMENT HEADER (POH_PROC_TYPE,
PO_NUMBER,
PO_SUPP,
ORDER_TYPE,
CLIENT_PO_NUMBER?,
POINT_OF_ORIGIN?,
SUP_CODE?,
ORIGIN?,
ISSUED_BY?,
PO_CURRENCY,
PO_RM_CODE,
PO_COUNTRY?,
EXPED_ILV_CODE?,
ILV_CODE?,
EV_CODE?,
CCP_CODE?,
PO_ACCOUNT_CODE?,
ORG_ETA_SITE_DATE?,
TECH_EVAL_COMP_DATE?,
BUYER,
EXPEDITER?,
TRAFFIC?,
READY_FOR_APPROVAL_IND?,
APPROVED_DATE?,
APPROVED_BY?,
PARENT_ORDER?,
PARENT_PO_NUMBER?,
PARENT_PO_SUPP?,
PARENT_ORIGIN_CODE?,
PARENT_ORDER_TYPE?,
ERP_MANAGED_IND?,
NLS*,
POH_OC*,
LINES*)>
<!ELEMENT POH_PROC_TYPE (#PCDATA)>
<!ELEMENT PO_NUMBER (#PCDATA)>
<!ELEMENT PO_SUPP (#PCDATA)>
<!ELEMENT ORDER_TYPE (#PCDATA)>
<!ELEMENT CLIENT_PO_NUMBER (#PCDATA)>
<!ELEMENT POINT_OF_ORIGIN (#PCDATA)>
<!ELEMENT SUP_CODE (#PCDATA)>
<!ELEMENT ORIGIN (#PCDATA)>
<!ELEMENT ISSUED_BY (#PCDATA)>
<!ELEMENT PO_CURRENCY (#PCDATA)>
<!ELEMENT PO_RM_CODE (#PCDATA)>
<!ELEMENT PO_COUNTRY (#PCDATA)>
<!ELEMENT EXPED_ILV_CODE (#PCDATA)>
<!ELEMENT ILV_CODE (#PCDATA)>
<!ELEMENT EV_CODE (#PCDATA)>
<!ELEMENT CCP_CODE (#PCDATA)>
<!ELEMENT PO_ACCOUNT_CODE (#PCDATA)>
<!ELEMENT ORG_ETA_SITE_DATE (#PCDATA)>
<!ELEMENT BUYER (#PCDATA)>
<!ELEMENT EXPEDITER (#PCDATA)>
<!ELEMENT TRAFFIC (#PCDATA)>
<!ELEMENT READY_FOR_APPROVAL_IND (#PCDATA)>
<!ELEMENT APPROVED_DATE (#PCDATA)>
<!ELEMENT APPROVED_BY (#PCDATA)>
<!ELEMENT PARENT_ORDER (#PCDATA)>
<!ELEMENT PARENT_PO_NUMBER (#PCDATA)>
<!ELEMENT PARENT_PO_SUPP (#PCDATA)>
<!ELEMENT PARENT_ORIGIN_CODE (#PCDATA)>
<!ELEMENT PARENT_ORDER_TYPE (#PCDATA)>
<!ELEMENT NLS (NLS_PROC_TYPE,
NLS_ID,
SHORT_DESC,
DESCRIPTION)>
<!ELEMENT NLS_PROC_TYPE (#PCDATA)>
<!ELEMENT NLS_ID (#PCDATA)>
<!ELEMENT SHORT_DESC (#PCDATA)>
<!ELEMENT DESCRIPTION (#PCDATA)>
<!ELEMENT POH_OC (POH_OC_PROC_TYPE,
POH_OC_CODE,
POH_COST_VALUE,
POH_OC_ACCOUNT_CODE?,
POH_OC_CURRENCY,
POH_OC_NLS*)>
<!ELEMENT POH_OC_PROC_TYPE (#PCDATA)>
<!ELEMENT POH_OC_CODE (#PCDATA)>
<!ELEMENT POH_COST_VALUE (#PCDATA)>
<!ELEMENT POH_OC_ACCOUNT_CODE (#PCDATA)>
<!ELEMENT POH_OC_CURRENCY (#PCDATA)>
<!ELEMENT POH_OC_NLS (POH_OC_NLS_PROC_TYPE,
POH_OC_NLS_ID,
POH_OC_SHORT_DESC,
POH_OC_DESCRIPTION)>
<!ELEMENT POH_OC_NLS_PROC_TYPE (#PCDATA)>
<!ELEMENT POH_OC_NLS_ID (#PCDATA)>
<!ELEMENT POH_OC_SHORT_DESC (#PCDATA)>
<!ELEMENT POH_OC_DESCRIPTION (#PCDATA)>
<!ELEMENT LINES (POLI_PROC_TYPE,
POLI_POS?,
POLI_SUB_POS?,
IDENT_CODE?,
POLI_QTY,
POLI_QTY_CODE,
POLI_UNIT_PRICE?,
SUPPLY_PRICE?,
INSTALL_PRICE?,
POLI_CURRENCY,
PRICE_BASE?,
POLI_UNIT_WEIGHT,
POLI_WEIGHT_CODE,
POLI_VOLUME?,
POLI_VOL_CODE?,
POLI_DIMENSIONS?,
FRT_CODE?,
FREIGHT_VALUE?,
POLI_COUNTRY?,
MANUFACTURER?,
CATALOG_NUMBER?,
PERCENT_US_CONTENT?,
TEC_PASSED_IND?,
EXPORT_LICENSE_REQ_IND?,
EXPORT_LICENSE_NUMBER?,
EXPORT_LICENSE_RECEIVED_DATE?,
POLI_ACCOUNT_CODE?,
ACCEPTED_IND?,
TAG_NUMBER?,
ITY_CODE?,
LAYOUT_SHORT?,
LAYOUT_LONG?,
PROM_CONTR_DATE?,
PARENT_POLI?,
PARENT_POLI_POS?,
PARENT_POLI_SUB_POS?,
REQ_LINE_ITEM?,
R_CODE?,
R_SUPP?,
R_ORIGIN_CODE?,
R_ACTUAL_IND?,
RLI_POS?,
RLI_SUB_POS?,
POLI_SPLIT_TAG?,
REQ_LINES*,
SHIPMENTS*,
POLI_OC*)>
<!ELEMENT POLI_PROC_TYPE (#PCDATA)>
<!ELEMENT POLI_POS (#PCDATA)>
<!ELEMENT POLI_SUB_POS (#PCDATA)>
<!ELEMENT IDENT_CODE (#PCDATA)>
<!ELEMENT POLI_QTY (#PCDATA)>
<!ELEMENT POLI_QTY_CODE (#PCDATA)>
<!ELEMENT POLI_UNIT_PRICE (#PCDATA)>
<!ELEMENT SUPPLY_PRICE (#PCDATA)>
<!ELEMENT INSTALL_PRICE (#PCDATA)>
<!ELEMENT POLI_CURRENCY (#PCDATA)>
<!ELEMENT PRICE_BASE (#PCDATA)>
<!ELEMENT POLI_UNIT_WEIGHT (#PCDATA)>
<!ELEMENT POLI_WEIGHT_CODE (#PCDATA)>
<!ELEMENT POLI_VOLUME (#PCDATA)>
<!ELEMENT POLI_VOL_CODE (#PCDATA)>
<!ELEMENT POLI_DIMENSIONS (#PCDATA)>
<!ELEMENT FRT_CODE (#PCDATA)>
<!ELEMENT FREIGHT_VALUE (#PCDATA)>
<!ELEMENT POLI_COUNTRY (#PCDATA)>
<!ELEMENT MANUFACTURER (#PCDATA)>
<!ELEMENT CATALOG_NUMBER (#PCDATA)>
<!ELEMENT PERCENT_US_CONTENT (#PCDATA)>
<!ELEMENT EXPORT_LICENSE_REQ_IND (#PCDATA)>
<!ELEMENT EXPORT_LICENSE_NUMBER (#PCDATA)>
<!ELEMENT EXPORT_LICENSE_RECEIVED_DATE (#PCDATA)>
<!ELEMENT POLI_ACCOUNT_CODE (#PCDATA)>
<!ELEMENT ACCEPTED_IND (#PCDATA)>
<!ELEMENT TAG_NUMBER (#PCDATA)>
<!ELEMENT ITY_CODE (#PCDATA)>
<!ELEMENT LAYOUT_SHORT (#PCDATA)>
<!ELEMENT LAYOUT_LONG (#PCDATA)>
<!ELEMENT PROM_CONTR_DATE (#PCDATA)>
<!ELEMENT PARENT_POLI (#PCDATA)>
<!ELEMENT PARENT_POLI_POS (#PCDATA)>
<!ELEMENT PARENT_POLI_SUB_POS (#PCDATA)>
<!ELEMENT REQ_LINE_ITEM (#PCDATA)>
<!ELEMENT R_CODE (#PCDATA)>
<!ELEMENT R_SUPP (#PCDATA)>
<!ELEMENT R_ORIGIN_CODE (#PCDATA)>
<!ELEMENT R_ACTUAL_IND (#PCDATA)>
<!ELEMENT RLI_POS (#PCDATA)>
<!ELEMENT RLI_SUB_POS (#PCDATA)>
<!ELEMENT POLI_SPLIT_TAG (#PCDATA)>
<!ELEMENT REQ_LINES (RLI_PROC_TYPE,
REQ_LINE_ITEM,
R_CODE,
R_SUPP,
R_ORIGIN_CODE,
R_ACTUAL_IND,
RLI_POS,
RLI_SUB_POS,
RLI_POLI_QTY)>
<!ELEMENT RLI_PROC_TYPE (#PCDATA)>
<!ELEMENT REQ_LINE_ITEM (#PCDATA)>
<!ELEMENT R_CODE (#PCDATA)>
<!ELEMENT R_SUPP (#PCDATA)>
<!ELEMENT R_ORIGIN_CODE (#PCDATA)>
<!ELEMENT R_ACTUAL_IND (#PCDATA)>
<!ELEMENT RLI_POS (#PCDATA)>
<!ELEMENT RLI_SUB_POS (#PCDATA)>
<!ELEMENT RLI_POLI_QTY (#PCDATA)>
<!ELEMENT SHIPMENTS (ISH_PROC_TYPE,
ITEM_SHIP_POS,
ITEM_SHIP_SUB_POS,
ITEM_SHIP_QTY?,
ITEM_SHIP_QTY_CODE?,
ITEM_SHIP_WEIGHT?,
ITEM_SHIP_WEIGHT_CODE?,
ITEM_SHIP_VOLUME?,
ITEM_SHIP_VOL_CODE?,
ITEM_SHIP_DIMENSIONS?,
DD_CODE?,
ITEM_SHIP_RM_CODE?,
FAB_LOCATION?,
FAB_SHOP_CNTRL_NUMBER?,
FAB_COMPLETE_PERCENT?,
FIFTY_PERCENT_FAB_COMP?,
REV_PROM_SHIP_DATE?,
MAJ_MATL_ORDER_DATE?,
MAJ_MATL_RECV_DATE?,
ACTUAL_FAB_START_DATE?,
PROM_FAB_COMP_DATE?,
ACTUAL_FAB_COMP_DATE?,
ACTUAL_SHIP_DATE?,
PRED_SHIP_DATE?,
PRED_ON_SITE_DATE?,
ACTUAL_ON_SITE_DATE?,
ACTUAL_CONTRACT_DATE?,
PROM_INSPECT_DATE?,
FINAL_INSPECT_DATE?,
READY_PREDICTED?,
READY_ACTUAL?,
PROM_CONTRACT_DATE?,
PROM_SHIP_DATE?,
REQ_SITE_DATE?,
ISH_EXPORT_LICENSE_REQ_IND?,
COMMENTS?,
ISH_SPLIT_TAG?)>
<!ELEMENT ISH_PROC_TYPE (#PCDATA)>
<!ELEMENT ITEM_SHIP_POS (#PCDATA)>
<!ELEMENT ITEM_SHIP_SUB_POS (#PCDATA)>
<!ELEMENT ITEM_SHIP_QTY (#PCDATA)>
<!ELEMENT ITEM_SHIP_QTY_CODE (#PCDATA)>
<!ELEMENT ITEM_SHIP_WEIGHT (#PCDATA)>
<!ELEMENT ITEM_SHIP_WEIGHT_CODE (#PCDATA)>
<!ELEMENT ITEM_SHIP_VOLUME (#PCDATA)>
<!ELEMENT ITEM_SHIP_VOL_CODE (#PCDATA)>
<!ELEMENT ITEM_SHIP_DIMENSIONS (#PCDATA)>
<!ELEMENT DD_CODE (#PCDATA)>
<!ELEMENT ITEM_SHIP_RM_CODE (#PCDATA)>
<!ELEMENT FAB_LOCATION (#PCDATA)>
<!ELEMENT FAB_SHOP_CNTRL_NUMBER (#PCDATA)>
<!ELEMENT FAB_COMPLETE_PERCENT (#PCDATA)>
<!ELEMENT FIFTY_PERCENT_FAB_COMP (#PCDATA)>
<!ELEMENT REV_PROM_SHIP_DATE (#PCDATA)>
<!ELEMENT MAJ_MATL_ORDER_DATE (#PCDATA)>
<!ELEMENT MAJ_MATL_RECV_DATE (#PCDATA)>
<!ELEMENT ACTUAL_FAB_START_DATE (#PCDATA)>
<!ELEMENT PROM_FAB_COMP_DATE (#PCDATA)>
<!ELEMENT ACTUAL_FAB_COMP_DATE (#PCDATA)>
<!ELEMENT ACTUAL_SHIP_DATE (#PCDATA)>
<!ELEMENT PRED_SHIP_DATE (#PCDATA)>
<!ELEMENT PRED_ON_SITE_DATE (#PCDATA)>
<!ELEMENT ACTUAL_ON_SITE_DATE (#PCDATA)>
<!ELEMENT ACTUAL_CONTRACT_DATE (#PCDATA)>
<!ELEMENT PROM_INSPECT_DATE (#PCDATA)>
<!ELEMENT FINAL_INSPECT_DATE (#PCDATA)>
<!ELEMENT READY_PREDICTED (#PCDATA)>
<!ELEMENT READY_ACTUAL (#PCDATA)>
<!ELEMENT PROM_CONTRACT_DATE (#PCDATA)>
<!ELEMENT PROM_SHIP_DATE (#PCDATA)>
<!ELEMENT REQ_SITE_DATE (#PCDATA)>
<!ELEMENT ISH_EXPORT_LICENSE_REQ_IND (#PCDATA)>
<!ELEMENT COMMENTS (#PCDATA)>
<!ELEMENT ISH_SPLIT_TAG (#PCDATA)>
<!ELEMENT POLI_OC (POLI_OC_PROC_TYPE,
POLI_OC_CODE,
POLI_COST_VALUE,
POLI_OC_ACCOUNT_CODE?,
POLI_OC_CURRENCY,
POLI_OC_NLS*)>
<!ELEMENT POLI_OC_PROC_TYPE (#PCDATA)>
<!ELEMENT POLI_OC_CODE (#PCDATA)>
<!ELEMENT POLI_COST_VALUE (#PCDATA)>
<!ELEMENT POLI_OC_ACCOUNT_CODE (#PCDATA)>
<!ELEMENT POLI_OC_CURRENCY (#PCDATA)>
<!ELEMENT POLI_OC_NLS (POLI_OC_NLS_PROC_TYPE,
POLI_OC_NLS_ID,
POLI_OC_SHORT_DESC,
POLI_OC_DESCRIPTION)>
<!ELEMENT POLI_OC_NLS_PROC_TYPE (#PCDATA)>
<!ELEMENT POLI_OC_NLS_ID (#PCDATA)>
<!ELEMENT POLI_OC_SHORT_DESC (#PCDATA)>
<!ELEMENT POLI_OC_DESCRIPTION (#PCDATA)>