Lets take an example :

user have to print Driver Name in Bill Format

go to self format > terms and condition > rename any field in driver name > then to go bill format > header > rename any command like L R no. and write manually driver name

Go to Master > MargSetup > Invoice Terms and Condition > Rename Field as per user requirement for Eg. Rename Delivery Field to Driver Name 

Note :  But user have to feed the Delivery Command for print Driver Name in Bill Format

Go to Master > MargSetup > Self Format > Feed Current Date(Year/month/date) >  Select Invoice Format > Select Format >Bill Format > Header > in Bill Detail Section >  Press F1 on Selected Field for Search > Delivery > <SL_DLV,20> Press F3 for Apply CTRL + W Save