Hi,
The following is taken directly from the C-source code comment:
/* Best representative NMR conformer, use #1 if not assigned in REMARK 210.
* Typical cases:
* BEST REPRESENTATIVE CONFORMER IN THIS ENSEMBLE : NULL [pdb28sp]
* BEST REPRESENTATIVE CONFORMER IN THIS ENSEMBLE : 1 [pdb2bj2]
* BEST REPRESENTATIVE CONFORMER IN THIS ENSEMBLE : 3 [pdb2lef]
* BEST REPRESENTATIVE CONFORMER IN THIS ENSEMBLE : 5 [pdb3php]
*
* For structures pdb1qby, pdb1djd & pdb1bjd, the REMARK 210 says the
* best representative conformer is #12 or #13, but the data file
* actually does not has that model. Reset inum to 1 for such cases.
*/
HTH,
Xiang-Jun