You can also search for / retrieve particular entries with -entry or -entry_batch:
-entry <String>
Comma-delimited search string(s) of sequence identifiers:
e.g.: 555, AC147927, 'gnl|dbname|tag', or 'all' to select all
sequences in the database
* Incompatible with: entry_batch, pig, info, list, recursive,
remove_redundant_dbs, list_outfmt, show_blastdb_search_path
-entry_batch <File_In>
Input file for batch processing (Format: one entry per line, seq id
followed by optional space-delimited specifier(s)
[range|strand|mask_algo_id]
* Incompatible with: entry, range, strand, mask_sequence_with, pig, info,
list, recursive, remove_redundant_dbs, list_outfmt,
show_blastdb_search_path