Fix a broken sentence
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167521 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/CommandGuide/FileCheck.rst b/docs/CommandGuide/FileCheck.rst
index 6fdc175..1d7a462 100644
--- a/docs/CommandGuide/FileCheck.rst
+++ b/docs/CommandGuide/FileCheck.rst
@@ -276,8 +276,9 @@
The first check line matches a regex (**%[a-z]+**) and captures it into
the variable "REGISTER". The second line verifies that whatever is in REGISTER
occurs later in the file after an "andw". FileCheck variable references are
-always contained in **[[ ]]** pairs, are named, and their names can be
-name, then it is a definition of the variable, if not, it is a use.
+always contained in **[[ ]]** pairs, and their names can be formed with the
+regex **[a-zA-Z][a-zA-Z0-9]***. If a colon follows the name, then it is a
+definition of the variable; otherwise, it is a use.
FileCheck variables can be defined multiple times, and uses always get the
latest value. Note that variables are all read at the start of a "CHECK" line