On the site https://coin.dance/blocks#blockDetails, there is a column
Coin Base Text with values like
Mined by AntPoolk9 Z4,b or
*3Zc/BTC.COM/mm.jn~OoBրn*e*@ for example. What does it mean? Is it equivalent to the nonce (because I thought, the nonce is always numeric)?
And where is this information stored? In each bitcoin block? And why?