Please make sure that the value you enter is valid for the datatype of the selected field. Also verify, that the context configuration for the project using this workflow will allow to modify the selected field.
 Otherwise, the transition may fail at execution time. 

Typically you will use text or numbers as value.

Cascading Select fields

For Cascading Select fields, you may either use the value of the option you would like to set, or it's id. In either case, no need to specify the parent option. For example:

• Vehicles
  • Car
  • Train
  • Bus
• Buildings
  • House
  • Skyscraper

Using Vehicles as the parameter for Field Value would set the field content to that very option. Same if you would choose Train. Or, assuming 10701 is the ID of House, then the option House will be set.

Special macros

If you use
%%CURRENT_USER%%
as the field value (exactly this, nothing more), the user who triggered the post function will be set as value.

If you use
%%CURRENT_DATETIME%%
as the field value (exactly this, nothing more), the current date and time will be set as value.

If you use
%%ADD_CURRENT_USER%%
as the field value (exactly this, nothing more), the user who triggered the post function will be appended to the existing field content.

Obsolete since 1.4.10: %%ADD_CURRENT_USER%%