question about quotation mark

FrameMaker 2020 includes improvements to Smart Quote functionality with specific language-specific Smart Quote preferences.

Once set, with Smart Quotes enabled and the proper dictionary specified in your styles, you'll get exactly what you need when inserting quote marks.

Here's the video I created for the feature:

https://www.youtube.com/watch?v=1yRuon3tb3E

https://helpx.adobe.com/framemaker/tutorials/language-specific-smart-quotes-video.html

If I try to do this by using the keyboard key 3 ( " ) , Frame Maker write « « (it does not write : «  »).

So in order to have : «  » , I am obliged to put a word between ( « ) and ( » ), and it works.

From Wikipedia:

Encoding[edit]

Double guillemets are present in many 8-bit extended ASCII character sets. They were at 0xAE and 0xAF (174 and 175) in CP437 on the IBM PC, and 0xC7 and 0xC8 in Mac OS Roman, and placed in several of ISO 8859 code pages (namely: -1, -7, -8, -9, -13, -15, -16) at 0xAB and 0xBB (171 and 187).

Microsoft added the single guillemets to CP1252 and similar sets used in Windows at 0x8B and 0x9B (139 and 155) (where the ISO standard placed C1 control codes).

The ISO 8859 locations were inherited by Unicode, which added the single guillemets at new locations:

• U+00AB « LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
• U+00BB » RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
• U+2039 ‹ SINGLE LEFT-POINTING ANGLE QUOTATION MARK
• U+203A › SINGLE RIGHT-POINTING ANGLE QUOTATION MARK

Despite their names, the characters are mirrored when used in right-to-left contexts.