Instead of using a tab for making a signature line, I used a table:
This is how to do it:
Create a 2x2 table.
Select the whole table and select Design → Borders → No Border.
Place your cursor in the upper left cell and select Design → Borders → Bottom Border.
Place the text you want to be displayed into the cell below.
Select Layout → The dialog box launcher on Cell Size → Options. Enter
0into the Left spinner.
Close all dialogs by pressing OK twice.
You can now write below this table. To add spacing below the table, place your cursor in the paragraph after the table and select Home → Line and Paragraph Spacing → Add Space Before Paragraph.
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