diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9c0104b785fe19a38ec603592b6ee9c04f19a544..a8406ef107082423e7faede2b4274a6d96513870 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,10 @@ v5.8.0
 **Python**
 - Transition bindings to use pybind11 (!1950)
 
+**Documentation**
+- Updated the User-guide with additional inofrmation for outflow BC, addressing the issue #103 (!1990)
+
+
 v5.7.0
 -----
 **Library**
diff --git a/docs/user-guide/solvers/incompressible-ns.tex b/docs/user-guide/solvers/incompressible-ns.tex
index 56a60b54f436d0be40b8d708df1a32f19417b69b..a6c4dec26620709a58c35d03ea3c1f277dd5f568 100644
--- a/docs/user-guide/solvers/incompressible-ns.tex
+++ b/docs/user-guide/solvers/incompressible-ns.tex
@@ -1242,7 +1242,9 @@ is replaced with
    \mathbf{u}^{*,n+1})
 \]
 where the default values are given by $\theta = 1,\alpha_1 = 0,\alpha_2 = 0$ and these values can be set through the parameters \inltt{OutflowBC\_theta},
-\inltt{OutflowBC\_alpha1} and \inltt{OutflowBC\_alpha2}. 
+\inltt{OutflowBC\_alpha1} and \inltt{OutflowBC\_alpha2}.  
+
+To have a closer look at how these parameters affect the boundary condition, let us assume $\alpha_1=\alpha_2=0$. Then, changing $\theta$ weighs between the first and second terms, where the first term is the original formulation for the outflow, while the second one accounts for the inflow via the dot product. In general, even with the existence of inflow at the boundary, using $\theta$ should be sufficient to handle the situation. When the inflow exist at the boundary, a starting point could be using $\theta=1/2$ with $\alpha$s being zero. The other two parameters, $\alpha_1$ and $\alpha_2$, provide additional flexibility in the formulation to possibly handle exceptional cases, and it is expected that, in general, they are not needed for simulations.
 
 Dong has also suggested convective like outflow conditions in
 \cite{Dong15} which can be enforced through a Robin type specification