General 
- Item name
- _pdbx_poly_seq_scheme.entry_id
- Category name
- pdbx_poly_seq_scheme
- Attribute name
- entry_id
- Required in PDB entries
- yes
- Used in currrent PDB entries
- No
Item Description 
Data Type 
- Data type code
- code
- Data type detail
- code item types/single words ...
- Primitive data type code
- char
- Regular expression
- [_,.;:"&<>()/\{}'`~!@#$%A-Za-z0-9*|+-]*