It is often useful to maintain a single main address.
Example: Anonymous user 'Pine' used 3P3QsMVK89JBNqZQv5zMAKG8FK3kJM4rjt as the Bitcoin address for a fund of 5104 Bitcoin, as described at https://pineapplefund.org/
A typical transaction is Bitcoin transaction f065cc0bbede00d3fb56d1dd704fb8e85e706f7d22cee5ec554136d452697331 where Pineapplefund transfers 300 BTC to a destination address and sends the entire remainder of the fund back to the original address, 3P3QsMVK89JBNqZQv5zMAKG8FK3kJM4rjt.
This transaction is seen in https://www.blockchain.com/btc/tx/f065cc0bbede00d3fb56d1dd704fb8e85e706f7d22cee5ec554136d452697331
Such transactions are very easy to generate on the command line.
Keeping the entire fund at a single address makes it extremely easy to publicly verify the development of the fund as grants are dispensed to recipients.
Consider the following output from a listunspent command
"txid" : "faadd4f329cc234a9b22368fe36131252002ff295ab466b9fdf4b2d1eb13d38c",
"vout" : 0,
"address" : "B69QTo216bcaA3SD2Da7Q9arThMy7Z8ayJ",
"account" : "",
"scriptPubKey" : "76a91412987f0ac5ac71d66bd672d6be6f227a0ec9895888ac",
"amount" : 1975796.00000000,
One can then send just 1000 SMLY to a destination address and keep the entire rest in the original address using
smileycoin-cli createrawtransaction '[{"txid":"faadd4f329cc234a9b22368fe36131252002ff295ab466b9fdf4b2d1eb13d38c","vout":0}]' '{"BEtZyyYqDXqmRJJ45nnL15cuASfiXg9Yik":1000,"B69QTo216bcaA3SD2Da7Q9arThMy7Z8ayJ":1974795}'
01000000018cd313ebd1b2f4fdb966b45a29ff0220253161e38f36229b4a23cc29f3d4adfa0000000000ffffffff0200e87648170000001976a9147283560a1a0e4d5ba2868e3ec7a7d98c6816d4e188ac00ab72479bb300001976a91412987f0ac5ac71d66bd672d6be6f227a0ec9895888ac00000000
smileycoin-cli signrawtransaction 01000000018cd313ebd1b2f4fdb966b45a29ff0220253161e38f36229b4a23cc29f3d4adfa0000000000ffffffff0200e87648170000001976a9147283560a1a0e4d5ba2868e3ec7a7d98c6816d4e188ac00ab72479bb300001976a91412987f0ac5ac71d66bd672d6be6f227a0ec9895888ac00000000
{
`` "hex" : "01000000018cd313ebd1b2f4fdb966b45a29ff0220253161e38f36229b4a23cc29f3d4adfa000000006b483045022100fcb221e7530002f91e0ff9e2e7b6ef70216f66cfcf8031302c0fc02ac4eba17702200bde8c7d7da8e74f57712915569ef9f05653352513c80daadd24b79a0c1454bd0121020b2242f11807f2d5404b0e17b63dedfd19600457d6555c2411b0da2b5b25e439ffffffff0200e87648170000001976a9147283560a1a0e4d5ba2868e3ec7a7d98c6816d4e188ac00ab72479bb300001976a91412987f0ac5ac71d66bd672d6be6f227a0ec9895888ac00000000",``
`` "complete" : true``
}
smileycoin-cli sendrawtransaction 01000000018cd313ebd1b2f4fdb966b45a29ff0220253161e38f36229b4a23cc29f3d4adfa000000006b483045022100fcb221e7530002f91e0ff9e2e7b6ef70216f66cfcf8031302c0fc02ac4eba17702200bde8c7d7da8e74f57712915569ef9f05653352513c80daadd24b79a0c1454bd0121020b2242f11807f2d5404b0e17b63dedfd19600457d6555c2411b0da2b5b25e439ffffffff0200e87648170000001976a9147283560a1a0e4d5ba2868e3ec7a7d98c6816d4e188ac00ab72479bb300001976a91412987f0ac5ac71d66bd672d6be6f227a0ec9895888ac00000000
1fa1ebcb69a361b56eeb283fb3adb87c0031ed88ca8b9e539fc3b33fcd225a38
The output from the last command was the TxId and as always the transaction can be viewed in any block explorer, e.g. https://chainz.cryptoid.info/smly/tx.dws?1fa1ebcb69a361b56eeb283fb3adb87c0031ed88ca8b9e539fc3b33fcd225a38.htm