HI Bibbi

This information is actually set by Joomla and not by the template. You will find an option for this under the 'SEO Settings' section of your 'Global Configuration'. For further details may I suggest the following couple of articles...

https://www.ostraining.com/blog/joomla/joomla-home-page-metadata/
http://joomlaseo.com/checklist/meta-data

Ciarán

Thanks for your reply. I do though already know where to insert the page title and where to deactivate the suffix.

I have, however, made a test of sites with J51 templates and discovered that sites without any title in the page display will always show the menu name + suffix. But on some sites with title in the page display the suffix will not show, and on others sites the suffix will be shown on some pages. On these sites I cannot find out why some of the pages will display the menu name + suffix, when the suffix is deactived and a title is inserted in the page display. All sites have suffix deactivated.
And this I find very strange.....

Hi Bibbi

You could try enabling one of the default Joomla templates and see if the issue remains just to ensure that this is not related to the template. I would be very surprised thou if it is as there is nothing within the template files that should have any bearing on your page titles. The again I have been wrong before

Ciarán