diff --git a/internal/request/request.go b/internal/request/request.go
index c1ebfc7..d521e03 100644
--- a/internal/request/request.go
+++ b/internal/request/request.go
@@ -3,6 +3,7 @@ package request
 import (
 	"encoding/json"
 	"fmt"
+	"git.xdrm.io/go/aicra/err"
 	"git.xdrm.io/go/aicra/response"
 	"log"
 	"net/http"
@@ -93,7 +94,7 @@ func FetchFormData(req *http.Request) map[string]interface{} {
 
 // LoadController tries to load a controller from its uri
 // checks for its given method ('Get', 'Post', 'Put', or 'Delete')
-func (i *Request) LoadController(method string) (func(response.Arguments, *response.Response) response.Response, error) {
+func (i *Request) LoadController(method string) (func(response.Arguments, *response.Response) response.Response, err.Error) {
 
 	/* (1) Build controller path */
 	path := strings.Join(i.Path, "-")
@@ -111,21 +112,21 @@ func (i *Request) LoadController(method string) (func(response.Arguments, *respo
 	/* (2) Try to load plugin */
 	p, err2 := plugin.Open(path)
 	if err2 != nil {
-		return nil, err2
+		return nil, err.UncallableController
 	}
 
 	/* (3) Try to extract method */
 	m, err2 := p.Lookup(method)
 	if err2 != nil {
-		return nil, err2
+		return nil, err.UncallableMethod
 	}
 
 	/* (4) Check signature */
 	callable, validSignature := m.(func(response.Arguments, *response.Response) response.Response)
 	if !validSignature {
-		return nil, fmt.Errorf("Invalid signature for method %s", method)
+		return nil, err.UncallableMethod
 	}
 
-	return callable, nil
+	return callable, err.Success
 
 }
diff --git a/server.go b/server.go
index 8eb176c..66c0979 100644
--- a/server.go
+++ b/server.go
@@ -38,7 +38,7 @@ func New(path string) (*Server, error) {
 
 }
 
-// Listens and binds the server to the given port
+// Listen binds the server to the given port
 func (s *Server) Listen(port uint16) error {
 
 	/* (1) Bind router */
@@ -83,7 +83,7 @@ func (s *Server) routeRequest(res http.ResponseWriter, httpReq *http.Request) {
 
 	/* (4) Check parameters
 	---------------------------------------------------------*/
-	parameters, paramError := s.ExtractParameters(req, method.Parameters)
+	parameters, paramError := s.extractParameters(req, method.Parameters)
 
 	// Fail if argument check failed
 	if paramError.Code != e.Success.Code {
@@ -93,8 +93,9 @@ func (s *Server) routeRequest(res http.ResponseWriter, httpReq *http.Request) {
 
 	/* (5) Load controller
 	---------------------------------------------------------*/
-	callable, err := req.LoadController(httpReq.Method)
-	if err != nil {
+	callable, callErr := req.LoadController(httpReq.Method)
+	if callErr.Code != e.Success.Code {
+		httpError(res, callErr)
 		log.Printf("[err] %s\n", err)
 		return
 	}
@@ -129,12 +130,12 @@ func (s *Server) routeRequest(res http.ResponseWriter, httpReq *http.Request) {
 
 }
 
-// ExtractParameters extracts parameters for the request and checks
+// extractParameters extracts parameters for the request and checks
 // every single one according to configuration options
-func (s *Server) ExtractParameters(req *request.Request, methodParam map[string]*config.Parameter) (map[string]interface{}, e.Error) {
+func (s *Server) extractParameters(req *request.Request, methodParam map[string]*config.Parameter) (map[string]interface{}, e.Error) {
 
 	// init vars
-	var err e.Error = e.Success
+	err := e.Success
 	parameters := make(map[string]interface{})
 
 	// for each param of the config
diff --git a/types.go b/types.go
index 5d05943..931459f 100644
--- a/types.go
+++ b/types.go
@@ -6,6 +6,10 @@ import (
 	"git.xdrm.io/go/aicra/middleware"
 )
 
+// Server represents an AICRA instance featuring:
+// * its type checkers
+// * its middlewares
+// * its configuration (controllers)
 type Server struct {
 	config     *config.Controller
 	Params     map[string]interface{}
diff --git a/util.go b/util.go
index e3aceb1..812c51b 100644
--- a/util.go
+++ b/util.go
@@ -55,8 +55,8 @@ func httpPrint(r http.ResponseWriter, res response.Response) {
 
 // Prints an error as HTTP response
 func httpError(r http.ResponseWriter, e err.Error) {
-	Json, _ := e.MarshalJSON()
+	JSON, _ := e.MarshalJSON()
 	r.Header().Add("Content-Type", "application/json")
-	r.Write(Json)
+	r.Write(JSON)
 	log.Printf("[http.fail] %s\n", e.Reason)
 }