Today I learned that there is an HTML entity called “thin space” that you can use when you need less space between two characters than the normal space.
The HTML code is  
Thin Space might be the most underrated HTML entity. It can be used for a name like J. K. Simmons. Without spacing, the J and K would seem too close together; with a regular space, they seem too far apart. Insert a thin space and it is just perfect. - Typography Manual