How to parse &quot;be an obligation or be prohibited&quot;, in para 76 in Case C-355/10 Parliament v. Council (Schengen Borders Code)?
<p>Robert Schütze. <a href="https://global.oup.com/academic/product/eu-law-9780198714927?cc=ca&amp;lang=en&amp;" rel="nofollow noreferrer"><em>European Union Law</em> 2 ed. 2018</a>. p. 324. All </p>

<blockquote>
  <p>76[.]  [...]    Depending on the political choices on the basis of which those rules are adopted, the powers of the border guards may vary significantly, and the exercise of those powers require authorisation, <strong>be an obligation or be prohibited</strong>, for example, in relation to applying enforcement measures, using force or conducting the persons apprehended to a specific location. In addition, where those powers concern the taking of measures against ships, their exercise is liable, depending on the scope of the powers, to interfere with the sovereign rights of third countries according to the flag flown by the ships concerned. Thus, the adoption of such rules constitutes a major development in the SBC system.</p>
</blockquote>

<p>This is quoted from <a href="http://curia.europa.eu/juris/document/document.jsf?docid=126363&amp;doclang=EN" rel="nofollow noreferrer">the judgment for Case C‑355/10</a> and <a href="https://www.google.com/search?q=%22require+authorisation%2C+be+an+obligation+or+be+prohibited%22" rel="nofollow noreferrer">many other websites</a> that has the omitted sentences at the outset.</p>

<p>I don't understand the syntax of the emboldened verb phrase. Is this ellipsis? What kind? <a href="https://en.wikipedia.org/wiki/Ellipsis_(linguistics)#Nominal_ellipsis" rel="nofollow noreferrer">Nominal</a>?</p>

<p>Did the judges intend to say</p>

<blockquote>
  <p>the powers of the border guards may be an obligation or be prohibited</p>
</blockquote>

<p>? The sentence's subject is "the powers of the border guards", thus "and the exercise of those powers require authorisation" interrupts and feels misplaced. I would've written</p>

<blockquote>
  <p>the powers of the border guards may vary significantly, <strong>may</strong> be an obligation or be prohibited, for example, in relation to applying enforcement measures, using force or conducting the persons apprehended to a specific location. <strong>The exercise of those powers require authorisation.</strong> </p>
</blockquote>

<h2>Your interpretation is wrong</h2>
<p>Its a list. It could be rewritten:</p>
<blockquote>
<p>... the exercise of those powers require:</p>
<ol>
<li><p>authorisation,</p>
</li>
<li><p>be an obligation or</p>
</li>
<li><p>be prohibited</p>
</li>
</ol>
</blockquote>
<p>That is, the border guard must be authorised to do X, must be required to always do X or must be prohibited from ever doing X.</p>

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