fnDerive = function defaultLinkTypes(sRel, sTarget) {
		// trim rel and finally return the trimmed value
		sRel = typeof sRel === "string" ? sRel.trim() : sRel;
		// if the app already specified a non-empty value for rel, or when there's no need
		// to restrict access to the opener, then leave rel unchanged
		if (!sRel && sTarget && sTarget !== "_self") {
			return "noopener noreferrer";
		}
		return sRel;
	}
Determines default link types for an &lt;a&gt; tag that comply with
best practices for cross-origin communication.

When the target will be opened in a new window,
and when no other link types have been specified in the <code>rel</code> attribute,
"noopener noreferrer" will be returned.

@param {string} sRel Caller defined link types for the <code>rel</code> attribute
@param {string} sTarget Value of the <code>target</code> attribute
@returns {string} Value for the <code>rel</code> attribute of the &lt;a&gt; tag
@private
@ui5-restricted
@alias module:sap/ui/util/defaultLinkTypes
@since 1.84