user8275: Link of the member
What is the character parameter in the above member of the class NRF24Network 
I cannot understand the use of it.

user4143: It's to identify the type of packet.  Apparently that code supports types of 0-127, and I guess (impossible to tell without digging into the code) that what you use them for is entirely up to you.  Basically it would typically define what is in the rest of the packet - again something which is up to you.

8275: <p><a href="http://maniacbug.github.io/RF24Network/structRF24NetworkHeader.html#a99e675f31589d72cf2fe036e77988026" rel="nofollow">Link of the member</a>
What is the character parameter in the above member of the class NRF24Network 
I cannot understand the use of it.</p>
 4143: <p>It's to identify the type of packet.  Apparently that code supports types of 0-127, and I guess (impossible to tell without digging into the code) that what you use them for is entirely up to you.  Basically it would typically define what is in the rest of the packet - again something which is up to you.</p>
