Lighting programmers are both creators and keepers of essential lighting data. Often this data may need to be combined with other versions of the data to create new forms of mutual data. Most lighting consoles provide various forms of merging, and almost anything is possible, from simple merging of data into a cue or palette/preset to complex merging of data from one show file to another. Lighting programmers need to understand what merging possibilities exist on the console and the procedures to correctly prepare and execute merging routines.
Read the full article at: http://plsn.com/articles/feeding-the-machines/merge-with-caution/