Created by Jerry Wang, last modified on May 08, 2015
Customizing裡針對transaction type WCBC和 item category group NORM有TAN和TAE兩個item category：
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 但是runtime時，dropdown list裡隻有1個entry TAN：
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 如何分析TAE被filter out的原因：
1. 找到item category綁定的field name：
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 2. 檢視GET_V的實作：
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 設定斷點，debug：
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 讀取order對應的orgamization model：
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 得到sales org和distribution channel：
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 拿到該product 的item category group:
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 3. 這裡的design是，根據process type和item category group唯一determine出一個item category：
即SPRO裡如下圖highlight的entry：
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 對于TAE，因為其entry對應的main item category維護了值TAC，是以不會被line 225的FM所return。
Item category dropdown list的determine - filtering 邏輯Created by Jerry Wang, last modified on May 08, 2015 
