Steps to reproduce:
The page will show the entire page title for that space. The logs will show the following error:
2018-10-11 10:28:33,107 WARN [http-nio-8090-exec-12] [support.core.impl.DefaultParameterAssistant] invoke Exception while processing an interceptor: '@seld' is not a recognized space category -- url: /display/OIPBP/SRSUP-2604 | page: 9994242 | traceId: 42cbbc0debe2aa0c | userName: confadmin | referer: http://localhost:8090/pages/editpage.action?pageId=9994242 | action: viewpage com.servicerocket.confluence.randombits.support.core.param.InterpretationException: '@seld' is not a recognized space category
Note that the page looks like it's working as expected since it's producing a result, but the result is inaccurate. There should be the same ERROR/Warning on the UI, not just the logs.