To create Drawing number in layout that reflected to Layout tab's name

1. create mtext anywhere in layout by type "t" and then hit spacebar and type anything (in this demonstration we typed"aaaaa")

2.Double click at text to show text editor window.  click "Field" button in text editor as shown

3.Now setting in "Field" pop up window
3.1 Field name column: Select"SystemVariable"
3.2 SystemVariable column: Select"Ctab"
3.3 Click OK and close

4.Text will be changed to be Layout's tab's name.  Try out to rename tab, this mtext with field setting will be changed automatically(if no change, please regen(type"re"then hit spacebar)).

5.Finish.