Creating Symbols from Sketches

From "Help Center" - "Create user-defined symbols": https://support.ptc.com/help/creo/ced_modeling/r20.9.0.0/en/index.html#page/ced_modeling/OSDM_Modules/3DDoc_symbol_user_defined.html 

Since you have been asking in the PTC Creo Element/Direct DRAFTING section I would like to point you to the SYMBOL_PART command of Drafting: 

file:///C:/Program%20Files/PTC/Creo%20Elements/Direct%20Drafting%2020.8.1.0/locale/en/me_help/me_helps.htm#SYMBOL_PART

C:\Program Files\PTC\Creo Elements\Direct Drafting 20.8.1.0\locale\en\me_help\me_helps.htm

(the version number in the parh need to be adapted according to your version)

But your file name with the extension ‘.sec’  make me hesitate!

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Vladimir’s answer is for the Annotation Module as part of PTC Creo Element/Direct MODELING.

https://support.ptc.com/help/creo/creo_pma/r12/usascii//index.html#page/fundamentals/fundamentals/About_File_Types.html 

Based on that list of file extensions a ‘sec’ file of a Creo Parametric sketch with name entered by you, or the default name. 

May be you might wanna ask your question in a more matching forum like:  https://community.ptc.com/t5/Creo-and-Creo-Parametric/ct-p/creoparametric

Creo Parametric should not be confused with Creo Elements/Direct Drafting, formerly CoCreate ME10 (2D) and or ME30 (3D) CAD Products.  You posted your question in the section for Creo Elements/Direct Drafting section.. The chance of getting helpful answers is better using an appropriate forum/section