I was drafting an opinion piece which discusses an Executive Order (EO) recently signed by US President Donald J. Trump, and found that referencing the document wasn't as simple as I expected.

The purpose and intent of this EO are in no way relevent to my question, and will not be discussed. Having spent a respectable number of years of my career interpreting and responding to various EOs as an industry advocate, determining if any production processes needed to be modified to comply with various EO's as Federal Employee, and finally ensuring my teammates and subordinates were fully briefed on, clearly understood the intent, and fully grasped any impacts a given EO may have on our daily battle rhythms to ensure my team fully complied with the intent of the President. 

That said, every single one I referenced or read through at the level I was at had been designated with a unique number. Some of these designations have become colloquial terms used to reference the requirements such as when asking about EO 12333, Intelligence Oversight requirements and ask "Are we all 12333 compliant?".

However when I went to reference this EO, which had just been signed by the President 3 days ago, there was no number designation anywhere in the document as it appeared on the White House website. 

At what point in the execution process of a Presidential Executive Order does the number designation get assigned (days after signing?), and which office is responsible for doing so?