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Your LimeSurvey version: LimeSurvey Cloud   Version 6.3.2
Own server or LimeSurvey hosting:
Survey theme/template:
==================Dear Community,I would like that the title of the survey does not appear on the top of the welcome messag or in any other place.Can you help me to implemet that? Thank you in advance for your helpful comments! Best,Kor

Extend your theme and adjust the appropriate TWIG or CSS files - www.limesurvey.org/manual/New_Template_System_in_LS3.x/en

It is pretty straightforward to add a theme option for this. We did this for the following themes which you can download at these links:
- Basic Reloaded: survey-consulting.com/product/limesurvey...late-basic-reloaded/
- Backy: survey-consulting.com/product/limesurvey-template-backy/
- Janus: survey-consulting.com/product/limesurvey-template-janus/

At these themes you can easily switch showing the survey title on or off for every survey as needed: