(1) ISSUE:
      * Most places, the spec includes the wording "the empy string" when it speak about 
          an @alt attribute that is considered empty. 

      * However, some some places it just says "empty", which is a phrase that is open to
         interpretation - e.g. it could include the space character to many readers.

      * Please  make sure that the spec says "empty string" everywhere.

      The liste below (3) points to the places where the spec says "empty" instead of "empty string".

(2) WHY THIS IS IMPORANT 
     1: USER AGENTS treat the <img> differently if the @alt is the empty string versus when 
         the @alt contains any other string. E.g. VoiceOver+VoiceOver always announces an <img>
         whose @alt is not the empty string. Other AT solutions work roughly the same way.  
         Thus, to be certain that the image's presence isn't announced, authors must use the
         empty string,  they cannot e.g. use a the space character as the content.
     2: CLARITY: If the @alt attribute only contains a white space character,  then many will 
          think of it as empty.
     3: CONSISTENCY: The spec text should be consistent - same wording everywhere.

(3) List of discovered places that needs fixing - with indication of how it can be repaired:

#img-load
   ]] If the src attribute is set and the alt attribute is set to a value that isn't empty [[
   SUGGESTED INSTEAD: … isn't the empty string

#a-link-or-button-containing-nothing-but-the-image
  ]] Except where otherwise specified, the alt attribute must be specified and its value must not be empty; the value must be an appropriate replacement for the image. [[
  SUGGESTED INSTEAD: … and its value must not be the empty string

#a-short-phrase-or-label-with-an-alternative-graphical-representation:-icons-logos
  ]]In those cases, the alt attribute must be present but must be empty. [[
  SUGGESTED INSTEAD: … but its value must be the empty string

#a-short-phrase-or-label-with-an-alternative-graphical-representation:-icons-logos
  ]] Here the icons are next to text that conveys the same meaning, so they have an empty alt attribute:[[
  SUGGESTED INSTEAD: … so they have an alt attribute with the empty string:

#a-short-phrase-or-label-with-an-alternative-graphical-representation:-icons-logos
  ]] If the logo is being used next to the name of the entity that it represents, then the logo is supplemental, and its alt attribute must instead be empty [[
  SUGGESTED INSTEAD: … and its alt attribute value must instead be the empty string

#table-aria-strong
  ]] img element whose alt attribute's value is empty[[
  SUGGESTED INSTEAD: … whose alt attribute value is the empty string