2.1.5 Add little or no space within strings of initials
“Names such as W.B. Yeats and J.C.L. Prillwitz need hair spaces, thin spaces or no spaces at all after the intermediary periods [full stops]. A normal word space follows the last period in the string.”
Hair spaces and thin spaces are two of the many space characters available in Unicode. Even if the character itself isn’t included in the current font, Unicode-aware browsers will display a good approximation. Here’s how to use hair spaces and thin spaces, respectively:
W. B. Yeats J. C. L. Prillwitz
Which renders as W. B. Yeats and J. C. L. Prillwitz. Unfortunately some browsers which are less Unicode-aware will show square placeholder symbols instead of the required spaces, so until support improves, no space at all is probably the way to go in this instance.