General 
- Item name
- _em_map.origin_z
- Category name
- em_map
- Attribute name
- origin_z
- Required in PDB entries
- yes
- Used in currrent PDB entries
- No
Item Description 
Data Type 
- Data type code
- int
- Data type detail
- int item types are the subset of numbers that are the negative
or positive integers.
- Primitive data type code
- numb
- Regular expression
- -?[0-9]+