diff --git a/Developer-documentation.md b/Developer-documentation.md
index ca5ca68..e62914a 100644
--- a/Developer-documentation.md
+++ b/Developer-documentation.md
@@ -83,16 +83,15 @@ This file contains our own MagicMemory library that provides memory allocation f
 
 `main` is the entrypoint of the previewer module.
 
-`perform_extraction` takes care of the preview extraction process: it calls parser and validator functions and other helper functions.
+`perform_extraction` takes care of the preview extraction process: it calls parser and validator functions and other helper functions. In theory, the size of a CAFF file can be really huge. In the case of our previewer, only files smaller than 512 megabytes are processed.
 
 ### utils.c
 
 `read_file_to_mem` is used to read CAFF files into memory.
 
-
 ### libtarga.c
 
-This files contains the [LibTarga](https://research.cs.wisc.edu/graphics/Gallery/LibTarga/) library by Alex Mohr.
+This file contains the [LibTarga](https://research.cs.wisc.edu/graphics/Gallery/LibTarga/) library by Alex Mohr.
 
 # CAFF previewer wrapper
 This module makes communication between the previewer and the web client possible.
@@ -107,6 +106,27 @@ The module provides only one endpoint:
 
 **Response:** If the preview extraction is successful, the response contains a single PNG image. The content type is set to `image/png`.
 
+## Integrity checking
+
+CAFF previewer wrapper provides two headers in the response that can be used to check the integrity of transferred files. These are the following:
+
+- `X-request-checksum` contains the md5 checksum of the received file.
+- `X-response-checksum` contains the md5 checksum of the converted file.
+
+These checksums can be used to detect errors during file transfer.
+
+## Preview process
+
+This section gives an overview of the preview creation process.
+
+### Converting CAFF to TGA
+
+After the wrapper receives a CAFF file, it uses the CAFF previewer written in C to extract a preview. The output of the previewer is a TGA file.
+
+### Converting TGA to PNG
+
+The wrapper uses ImageMagick to convert the TGA file (output of the previewer) to PNG. This step is done because PNG is a more suitable image format for the web application than TGA.
+
 # Web application
 This module provides the web UI for the users.