diff --git a/Automake.lyx b/Automake.lyx
index 69046bb..e0c1f87 100644
--- a/Automake.lyx
+++ b/Automake.lyx
@@ -995,5 +995,286 @@ make bindir='' libdir='' install
  
 \end_layout
 
+\begin_layout Subsection
+Prefix Not Associated with Installation
+\end_layout
+
+\begin_layout Standard
+Sometimes,
+ we don't want certain products to installed anywhere.
+ That's why we have certain prefix which are not associated with any installation location.
+ There are 3 main such prefix:
+\end_layout
+
+\begin_layout Itemize
+
+\family typewriter
+noinst
+\family default
+:
+ This signifies that the product listed in a variable with this prefix is not to be installed anywhere in the system after the build process.
+ It could be a 
+\shape italic
+convenience
+\shape default
+ static library which is only used to build a final product.
+\end_layout
+
+\begin_layout Itemize
+
+\family typewriter
+check
+\family default
+:
+ The products listed will be build only when 
+\family typewriter
+make check
+\family default
+ command is used.
+ These products are only build for testing purpose.
+\end_layout
+
+\begin_layout Itemize
+
+\family typewriter
+EXTRA
+\family default
+:
+ This signifies the list of products which may be conditionally build and eventually,
+ installed.
+ This types of configuration control is possible via 
+\family typewriter
+\shape slanted
+configure
+\family default
+\shape default
+ script where we pass some argument to it and prompts to build some 
+\begin_inset Quotes eld
+\end_inset
+
+extra
+\begin_inset Quotes erd
+\end_inset
+
+ products.
+ However,
+ enabling such feature of autoconf and automake is not as simple as above two.
+ Go through the below illustration:
+\end_layout
+
+\begin_layout Standard
+\begin_inset CommandInset line
+LatexCommand rule
+offset "0.5ex"
+width "100col%"
+height "1pt"
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset listings
+lstparams "basicstyle={\rmfamily}"
+inline false
+status open
+
+\begin_layout Plain Layout
+AC_INIT(...)
+\end_layout
+
+\begin_layout Plain Layout
+...
+\end_layout
+
+\begin_layout Plain Layout
+optional_programs=
+\end_layout
+
+\begin_layout Plain Layout
+AC_SUBST([optional_programs])
+\end_layout
+
+\begin_layout Plain Layout
+...
+\end_layout
+
+\begin_layout Plain Layout
+if test "x$(build_opt_prog)" = xyes;
+ then
+\end_layout
+
+\begin_layout Plain Layout
+  optional_programs=$(optional_programs) optprog		
+\lang american
+### 1 ###
+\end_layout
+
+\begin_layout Plain Layout
+fi
+\end_layout
+
+\begin_layout Plain Layout
+...
+\end_layout
+
+\begin_layout Plain Layout
+
+\end_layout
+
+\begin_layout Plain Layout
+\begin_inset Caption Standard
+
+\begin_layout Plain Layout
+A shell script code in configure.ac for building 
+\series bold
+optprog
+\series default
+ product conditionally.
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+
+\begin_inset CommandInset line
+LatexCommand rule
+offset "0.5ex"
+width "100col%"
+height "1pt"
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset space \space{}
+\end_inset
+
+
+\begin_inset CommandInset line
+LatexCommand rule
+offset "0.5ex"
+width "100col%"
+height "1pt"
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset listings
+inline false
+status open
+
+\begin_layout Plain Layout
+EXTRA_PROGRAMS = optprog						### 2 ###
+\end_layout
+
+\begin_layout Plain Layout
+bin_PROGRAMS = myprog $(optional_programs)	  ### 3 ###
+\begin_inset Caption Standard
+
+\begin_layout Plain Layout
+Using the EXTRA prefix to conditionally build products in Makefile.am
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+
+\begin_inset CommandInset line
+LatexCommand rule
+offset "0.5ex"
+width "100col%"
+height "1pt"
+
+\end_inset
+
+In Listing 6 ### 1 ###,
+ 
+\series bold
+optprog
+\series default
+ is appended to an Autoconf substitution variable called 
+\family sans
+optional_program
+\family default
+.
+ The 
+\family sans
+EXTRA_PROGRAMS 
+\family default
+variable at ### 2 ### in Listing 7 list 
+\family sans
+optprog,
+ 
+\family default
+as a product that may or may not be build.
+ This redundant information of 
+\family sans
+EXTRA_PROGRAMS 
+\family default
+in Makefile.am make it ensure that Automake knows that optprog is a optional product and make the resultant Makefile with appropriate script.
+ This make sure that even if 
+\series bold
+optprog
+\series default
+ is not mentioned in 
+\family typewriter
+$(optional_programs)
+\family default
+ variable in some build.
+\end_layout
+
+\begin_layout Subsection
+Primaries
+\end_layout
+
+\begin_layout Standard
+
+\shape italic
+Primaries
+\shape default
+ represent type of product which is generated by this build system.
+ That's it!
+ What are these type of files?
+ 
+\begin_inset Newline newline
+\end_inset
+
+These files can be executable,
+ libraries,
+ config files in terms of xml,
+ json and event normal txt files.
+ Wait,
+ normal txt files?
+ Well,
+ what it means is that some products (not exactly) of build system are not actually generated by the build system.
+ These are part of the project and we will need these files while executing the software in our system after the build process of that software.
+ For example,
+ C or C++ language have the prototype of the function or API written in header files (.h or .hpp) which allows the user of the library to make there software aware of these API before using it and enables in linking the implementation to the function calls while in the linking process of the build system.
+ So,
+ the main intent of this long boring example is to provide a context on why we have different kind of primaries as this helps in differentiating the type of product to Automake and hence generate rules in resultant Makefile accordingly.
+ Interestingly,
+ we can define our own primaries,but beware,
+ we need to write the rules for those on our own in Makefile.am.
+\end_layout
+
+\begin_layout Standard
+Let us see the default primaries supported by Automake.
+\end_layout
+
 \end_body
 \end_document