diff --git a/src/index/exefetcher.cpp b/src/index/exefetcher.cpp
index cc5ea2e7..ab6feb4c 100644
--- a/src/index/exefetcher.cpp
+++ b/src/index/exefetcher.cpp
@@ -47,10 +47,12 @@ public:
         args.push_back(idoc.ipath);
         int status = ecmd.doexec1(args, 0, &out);
         if (status == 0) {
-            LOGDEB("EXEDocFetcher::Internal: got ["  << (out) << "]\n" );
+            LOGDEB("EXEDocFetcher::Internal: got [" << out << "]\n");
             return true;
         } else {
-            LOGERR("EXEDOcFetcher::fetch: "  << (bckid) << ": "  << (stringsToString(cmd)) << " failed for "  << (udi) << " "  << (idoc.url) << " "  << (idoc.ipath) << "\n" );
+            LOGERR("EXEDOcFetcher::fetch: " << bckid << ": " <<
+                   stringsToString(cmd) << " failed for " << udi << " " <<
+                   idoc.url << " " << idoc.ipath << "\n");
             return false;
         }
     }
@@ -59,7 +61,8 @@ public:
 EXEDocFetcher::EXEDocFetcher(const EXEDocFetcher::Internal& _m)
 {
     m = new Internal(_m);
-    LOGDEB("EXEDocFetcher::EXEDocFetcher: fetch is "  << (stringsToString(m->sfetch)) << "\n" );
+    LOGDEB("EXEDocFetcher::EXEDocFetcher: fetch is " <<
+           stringsToString(m->sfetch) << "\n");
 }
 
 bool EXEDocFetcher::fetch(RclConfig* cnf, const Rcl::Doc& idoc, RawDoc& out)
@@ -82,12 +85,12 @@ EXEDocFetcher *exeDocFetcherMake(RclConfig *config, const string& bckid)
     static ConfSimple *bconf;
     if (!bconf) {
         string bconfname = path_cat(config->getConfDir(), "backends");
-        LOGDEB("exeDocFetcherMake: using config in "  << (bconfname) << "\n" );
+        LOGDEB("exeDocFetcherMake: using config in " << bconfname << "\n");
         bconf = new ConfSimple(bconfname.c_str(), true);
         if (!bconf->ok()) {
             delete bconf;
             bconf = 0;
-            LOGDEB("exeDocFetcherMake: bad/no config: "  << (bconfname) << "\n" );
+            LOGDEB("exeDocFetcherMake: bad/no config: " << bconfname << "\n");
             return 0;
         }
     }
@@ -97,28 +100,29 @@ EXEDocFetcher *exeDocFetcherMake(RclConfig *config, const string& bckid)
 
     string sfetch;
     if (!bconf->get("fetch", sfetch, bckid) || sfetch.empty()) {
-        LOGERR("exeDocFetcherMake: no 'fetch' for ["  << (bckid) << "]\n" );
+        LOGERR("exeDocFetcherMake: no 'fetch' for [" << bckid << "]\n");
         return 0;
     }
     stringToStrings(sfetch, m.sfetch);
     // We look up the command as we do for filters for now
     m.sfetch[0] = config->findFilter(m.sfetch[0]);
     if (!path_isabsolute(m.sfetch[0])) {
-        LOGERR("exeDocFetcherMake: "  << (m.sfetch[0]) << " not found in exec path or filters dir\n" );
+        LOGERR("exeDocFetcherMake: " << m.sfetch[0] <<
+               " not found in exec path or filters dir\n");
         return 0;
     }
 
     string smkid;
     if (!bconf->get("makesig", smkid, bckid) || smkid.empty()) {
-        LOGDEB("exeDocFetcherMake: no 'makesig' for ["  << (bckid) << "]\n" );
+        LOGDEB("exeDocFetcherMake: no 'makesig' for [" << bckid << "]\n");
         return 0;
     }
     stringToStrings(smkid, m.smkid);
     m.smkid[0] = config->findFilter(m.smkid[0]);
     if (!path_isabsolute(m.smkid[0])) {
-        LOGERR("exeDocFetcherMake: "  << (m.smkid[0]) << " not found in exec path or filters dir\n" );
+        LOGERR("exeDocFetcherMake: " << m.smkid[0] <<
+               " not found in exec path or filters dir\n");
         return 0;
     }
     return new EXEDocFetcher(m);
 }
-
diff --git a/src/index/exefetcher.h b/src/index/exefetcher.h
index 30e43d3d..d1682a8e 100644
--- a/src/index/exefetcher.h
+++ b/src/index/exefetcher.h
@@ -23,7 +23,16 @@ class RclConfig;
 
 /** 
  * A fetcher which works by executing external programs, defined in a
- * configuration file:
+ * configuration file.
+ * At this point this is only used with the sample python mbox indexer,
+ * to show how recoll can work with completely external data extraction code.
+ *
+ * Configuration: The external indexer sets the 'rclbes' recoll field
+ * (backend definition, can be FS or BGL -web- in standard recoll) to
+ * a unique value (e.g. MBOX for the python sample). A 'backends' file
+ * in the configuration directory then links the 'rclbes' value with
+ * commands to execute for fetching the data, which recoll uses at
+ * query time for previewing and opening the document.
  */
 class EXEDocFetcher : public DocFetcher {
     class Internal;
@@ -32,7 +41,7 @@ class EXEDocFetcher : public DocFetcher {
 
     virtual bool fetch(RclConfig* cnf, const Rcl::Doc& idoc, RawDoc& out);
     /** Calls stat to retrieve file signature data */
-    virtual bool makesig(RclConfig* cnf, const Rcl::Doc& idoc, std::string& sig);
+    virtual bool makesig(RclConfig* cnf, const Rcl::Doc& idoc,std::string& sig);
     friend EXEDocFetcher *exeDocFetcherMake(RclConfig *, const std::string&);
 private:
     Internal *m;
diff --git a/src/index/fetcher.cpp b/src/index/fetcher.cpp
index 99d60735..0375a98a 100644
--- a/src/index/fetcher.cpp
+++ b/src/index/fetcher.cpp
@@ -42,7 +42,7 @@ DocFetcher *docFetcherMake(RclConfig *config, const Rcl::Doc& idoc)
     } else {
         DocFetcher *f = exeDocFetcherMake(config, backend);
         if (!f) {
-            LOGERR("DocFetcherFactory: unknown backend ["  << (backend) << "]\n" );
+            LOGERR("DocFetcherFactory: unknown backend [" << backend << "]\n");
         }
 	return f;
     }
diff --git a/src/index/fetcher.h b/src/index/fetcher.h
index b6e540cb..7810ad34 100644
--- a/src/index/fetcher.h
+++ b/src/index/fetcher.h
@@ -28,14 +28,19 @@ class RclConfig;
  * Generic interface to retrieve the data for a document designated by
  * its index data (udi/ipath/url).  This is used to retrieve the data
  * for previewing. The actual implementation is specific to the kind
- * of backend (file system, beagle cache, others?...), and the
- * implementation may of course may share code with the indexing-time
+ * of backend (file system, web cache, others?...), and the
+ * implementation may of course share code with the indexing-time
  * functions from the specific backend.
  *
- * This is used to give access the raw document container (either as a
+ * This normally gives access the raw document container (either as a
  * file or as a memory block). The Internfile code will then further
  * process it to get to the actual document, especially if
  * de-embedding is involved.
+ *
+ * The DATADIRECT document kind, which holds final extracted data, is only 
+ * returned when using an external indexer (only the python demo sample at 
+ * this point), in which case the whole extraction is performed by the 
+ * external code.
  */
 class DocFetcher {
 public:
@@ -71,7 +76,8 @@ public:
     virtual ~DocFetcher() {}
 };
 
-/** Return an appropriate fetcher object given the backend string identifier */
+/** Return an appropriate fetcher object given the backend string 
+ * identifier inside idoc*/
 DocFetcher *docFetcherMake(RclConfig *config, const Rcl::Doc& idoc);
 
 #endif /* _FETCHER_H_INCLUDED_ */
diff --git a/src/internfile/extrameta.cpp b/src/internfile/extrameta.cpp
index 12070172..d49d871a 100644
--- a/src/internfile/extrameta.cpp
+++ b/src/internfile/extrameta.cpp
@@ -33,7 +33,8 @@ static void docfieldfrommeta(RclConfig* cfg, const string& name,
 			     const string &value, Rcl::Doc& doc)
 {
     string fieldname = cfg->fieldCanon(name);
-    LOGDEB0("Internfile:: setting ["  << (fieldname) << "] from cmd/xattr value ["  << (value) << "]\n" );
+    LOGDEB0("Internfile:: setting [" << fieldname <<
+            "] from cmd/xattr value [" << value << "]\n");
     if (fieldname == cstr_dj_keymd) {
 	doc.dmtime = value;
     } else {
@@ -44,15 +45,17 @@ static void docfieldfrommeta(RclConfig* cfg, const string& name,
 void reapXAttrs(const RclConfig* cfg, const string& path, 
 		map<string, string>& xfields)
 {
-    LOGDEB2("reapXAttrs: ["  << (path) << "]\n" );
+    LOGDEB2("reapXAttrs: [" << path << "]\n");
 #ifndef _WIN32
     // Retrieve xattrs names from files and mapping table from config
     vector<string> xnames;
     if (!pxattr::list(path, &xnames)) {
         if (errno == ENOTSUP) {
-            LOGDEB("FileInterner::reapXattrs: pxattr::list: errno "  << (errno) << "\n" );
+            LOGDEB("FileInterner::reapXattrs: pxattr::list: errno " <<
+                   errno << "\n");
         } else {
-            LOGERR("FileInterner::reapXattrs: pxattr::list: errno "  << (errno) << "\n" );
+            LOGERR("FileInterner::reapXattrs: pxattr::list: errno " <<
+                   errno << "\n");
         }
 	return;
     }
@@ -74,12 +77,13 @@ void reapXAttrs(const RclConfig* cfg, const string& path,
 	}
 	string value;
 	if (!pxattr::get(path, *it, &value, pxattr::PXATTR_NOFOLLOW)) {
-	    LOGERR("FileInterner::reapXattrs: pxattr::get failedfor "  << ((*it)) << ", errno "  << (errno) << "\n" );
+	    LOGERR("FileInterner::reapXattrs: pxattr::get failed for " << *it
+                   << ", errno " << errno << "\n");
 	    continue;
 	}
 	// Encode should we ?
 	xfields[key] = value;
-	LOGDEB2("reapXAttrs: ["  << (key) << "] -> ["  << (value) << "]\n" );
+	LOGDEB2("reapXAttrs: [" << key << "] -> [" << value << "]\n");
     }
 #endif
 }