N3733 US-1 says:

In lists of specifications, the use of anonymous bullets makes it difficult (in correspondence and speech) to refer to individual list items. Moreover, the longer the list, the greater the opportunity to mistake the structure, most especially in the presence of bullets in sublists.

It goes on to propose:

In all lists of bulleted items, provide a distinct numbered or lettered identification in place of each bullet. Because paragraphs are already numbered, it seems best to use letters for top-level list items within paragraphs and then to use Roman numerals for any sublist items. (A few parts of the Standard already do this.)