Annie,
As an event photographer I have to ID the guests. I ask for the Guest List in advance.
Can I create a Code Replacement for each event I shoot?
My clients want the guest's name in the Filename, for example: DSC_1234-Annie Watt, John Smith, Alice Smith
Certainly, but you're going to have to be able to identify the person in the photo and enter the shorthand version of their name and Code Replacement will replace your short code with the longer replacement. If you have a large number of guests but you will only have a photo or two of them, then Code Replacement won't be all that useful to you. Better would be to simply use an unused IPTC field to enter the person's name (or Persons Shown) on each picture and then use the corresponding IPTC variable in your renaming. For instance, if you're going through all of your pictures, identifying guests, you could enter their name in the Edit Status field. Then once all pictures have a name assigned to the Edit Status field, you would select them all, then use the Rename command and enter this as the rename string:
{filenamebase)-{editstatus}
And you would end up with file names just as you described.
Code Replacement is generally used when you want to type something short and have it replaced with something much longer. You could use it in your case as well depending on how tedious you find it to enter the guests' names. But basically there is no point in creating a Code Replacement file that looks like this:
Annie Watt[tab]Annie Watt
John Smith[tab]John Smith
Alice Smith[tab]Alice Smith
...
If you had more information about them that you would want expanded like so:
Annie Watt[tab]Chief Photographer, Annie Watt Studios
then Code Replacement would make more sense.
I hope this helps you, please feel free to ask more questions.
-Kirk