I tried to save a report with a space in the name and it got this funny error message:
"The name you entered is not valid.A valid name starts with an alphabet and contains alphabets, digits or underscores."
I'm quite certain Pega doesn't want me to enter a name like "abcdefghijklmnopqrstuvwxyz_My_Report_Name_abcdefghijklmnopqrstuvwxyz"
In stead I think it should read:
"The name you entered is not valid. A valid name starts with a letter from the alphabet and contains only letters from the alphabet, digits or underscores."