@IF(%%tfa_Subject%%="TP",@CONCATENATE("%%tfa_PN%%," (",%%tfa_StartDate1%%,")"," for ",%%tfa_Pleaseenteryourn1%%),@IF(%%tfa_Subject%%="TT",@CONCATENATE("TT: ",%%tfa_Starts%%," to ",%%tfa_Destination%%," (",%%tfa_StartDate1%%,")"),%%tfa_Pleasespecify%%))
This is a variation on my two value subject line, which does work:
@IF(%%tfa_Subject%%="TT",@CONCATENATE("TTs: ",%%tfa_Starts%%," to ",%%tfa_Destination%%," (",%%tfa_StartDate1%%,")"),%%tfa_Pleasespecify%%)
I've had three options working before but only with two possible subject values:
@IF((@OR(%%tfa_Subject%%="Question",%%tfa_Subject%%="Other")),%%tfa_MessageSubject%%,%%tfa_PackageName%%) from %%tfa_Pleaseenteryourn1%%
If you're still having trouble, this might be better handled in a support request, but let me take a crack at here for anyone who comes along:
1. It looks like you're getting a bit tripped up on matched quotes syntax. Here in your original two value line:
@IF(%%tfa_Subject%%="TT",@CONCATENATE("TTs: ",%%tfa_Starts%%," to ",%%tfa_Destination%%," (",%%tfa_StartDate1%%,")"),%%tfa_Pleasespecify%%)
You get it right, but in the three value:
@IF(%%tfa_Subject%%="TP",@CONCATENATE("%%tfa_PN%%," (",%%tfa_StartDate1%%,")"," for ",%%tfa_Pleaseenteryourn1%%),@IF(%%tfa_Subject%%="TT",@CONCATENATE("TT: ",%%tfa_Starts%%," to ",%%tfa_Destination%%," (",%%tfa_StartDate1%%,")"),%%tfa_Pleasespecify%%))
You've got what looks like an extra quote to me: @CONCATENATE("%%tfa_PN%%