26171
( BELL codes could be inserted in those sequences to signal to the remote operator that a new message was coming or that transmission of a message was terminated ) .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities:  
Answer:
 None