The parameter is used in the relative floor drift control. According to the selected option, the control is made according to the equation 4.34a or 4.34b. Relative floor drift limit values are reduced by half in the connection made without the use of flexible joint, that is type A. When the flexible course is used, the limit value is doubled, considering that the joint placed between the load-bearing system and the wall in case of an earthquake will prevent the walls from cracking in the event of an earthquake. You can decide on the option according to the application to be made. Or, if you are having problems due to the relative floor displacement controls, you can explain the joint application requirement in the static and architectural project details and notes, and you can solve it with option b.