Making span names bold & linking transactions

Still exploring how capable elasic apm is of integrating manual instrumentation. Looking at some examples, I could see the name some spans written bold - mostly HTTP related spans, like shown here:

Is there any way of influencing this for a custom span created with the OpenTelemetry Java SDK?

I was hoping, this would be possible by "linking" transactions but could not find anything related...

The UI displays transactions (= the entry span into a service) in bold. There is no other way of influencing this rendering.

I was hoping, this would be possible by "linking" transactions but could not find anything related...

I don't understand what you mean here, could you elaborate more? Is what you are trying somehow related to OpenTelemetry span-links?

Thanks, this might be it. What I was trying to refer to was how I could "link" a transaction A inside another transaction B. Meaning transaction B appears as a "bold span" inside trace A.

I guess this applies for the "GET/api", "APIRestController#topProducts", "DispatcherServlet#doGet" and "GET opbeans.views.stats" spans in the screenshot I provided above.