lots of markup nits, most commonly Unix/unix --> \UNIX
diff --git a/Doc/api/intro.tex b/Doc/api/intro.tex
index 2ed38a0..1295e5f 100644
--- a/Doc/api/intro.tex
+++ b/Doc/api/intro.tex
@@ -597,11 +597,11 @@
Compiling the interpreter with the \csimplemacro{Py_DEBUG} macro
defined produces what is generally meant by "a debug build" of Python.
-\csimplemacro{Py_DEBUG} is enabled in the Unix build by adding
+\csimplemacro{Py_DEBUG} is enabled in the \UNIX{} build by adding
\longprogramopt{with-pydebug} to the \file{configure} command. It is also
implied by the presence of the not-Python-specific
\csimplemacro{_DEBUG} macro. When \csimplemacro{Py_DEBUG} is enabled
-in the Unix build, compiler optimization is disabled.
+in the \UNIX{} build, compiler optimization is disabled.
In addition to the reference count debugging described below, the
following extra checks are performed: