Bug 68011 [java search] "Search the JRE System Libraries" looks like a local preference but behaves as a global one... [search]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/JavaSearchPage.java
Composite result= new Composite(parent, SWT.NONE);
		
		GridLayout layout= new GridLayout(2, false);
		layout.horizontalSpacing= 10;
		result.setLayout(layout);
		
		Control expressionComposite= createExpression(result);
		expressionComposite.setLayoutData(new GridData(GridData.FILL, GridData.CENTER, true, false, 2, 1));
		
		Label separator= new Label(result, SWT.NONE);
		separator.setVisible(false);
		GridData data= new GridData(GridData.FILL, GridData.FILL, false, false, 2, 1);
		data.heightHint= convertHeightInCharsToPixels(1) / 3;
		separator.setLayoutData(data);
		
		Control searchFor= createSearchFor(result);
		searchFor.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, false, 1, 1));
		Control limitTo= createLimitTo(result);
		limitTo.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, false, 1, 1));
		fSearchJRE= new Button(result, SWT.CHECK);
		fSearchJRE.setText(SearchMessages.SearchPage_searchJRE_label); 
		fSearchJRE.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent e) {
				setSearchJRE(fSearchJRE.getSelection());
			}
		});
		fSearchJRE.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false, 2, 1));