diff --git a/BUGS.md b/BUGS.md
index 0e06b53..d9933ac 100644
--- a/BUGS.md
+++ b/BUGS.md
@@ -19,6 +19,9 @@ ou usar push (websockets?)
 
 # TODO
 
+- gerar teste qd o prof autoriza.
+- enviar resposta de cada pergunta individualmente.
+
 - experimentar gerador de svg que inclua no markdown da pergunta e ver se funciona. 
 - imagens jpg/png nas perguntas.
 - suportar cotacao to teste diferente de 20 (e.g. para juntar perguntas em papel). opcao "points: 18" que normaliza total para 18 em vez de 20.
diff --git a/README.md b/README.md
index ccd4db5..448a5cd 100644
--- a/README.md
+++ b/README.md
@@ -4,9 +4,9 @@
 2. [Running a demo](#running-a-demo)
 3. [Troubleshooting](#troubleshooting)
 
-## Installation
+## 1. Installation
 
-### Requirements
+### 1.1 Requirements
 
 The webserver is a python application and requires `python3.6` and `pip` to be installed, plus the following additional packages:
 
@@ -16,13 +16,14 @@ The webserver is a python application and requires `python3.6` and `pip` to be i
 - Pygments
 - SQLAlchemy
 - bcrypt
+- markdown
 
 These can be installed for a single user (recommended), in a python virtual environment or system wide.
 
 #### Installing packages for a single user (recommended)
 
 ```.bash
-pip3 install --user tornado mistune pyyaml pygments sqlalchemy bcrypt
+pip3 install --user tornado mistune pyyaml pygments sqlalchemy bcrypt markdown
 ```
 
 #### Installing packages in a virtual environment (alternative)
@@ -31,7 +32,7 @@ pip3 install --user tornado mistune pyyaml pygments sqlalchemy bcrypt
 pyvenv-3.6 venv/perguntations              # or other virtualenv directory
 source venv/perguntations/bin/activate     # activate virtualenv
 
-pip3 install tornado mistune pyyaml pygments sqlalchemy bcrypt
+pip3 install tornado mistune pyyaml pygments sqlalchemy bcrypt markdown
 ```
 
 #### Installing packages system wide (alternative)
@@ -51,7 +52,7 @@ port install py36-py36-tornado py36-mistune? py36-yaml py36-pygments...
 ```
 
 
-### Install and setup perguntations
+### 1.2 Install and setup perguntations
 
 There is no installer, pip or otherwise. It's still in development and has to be run from sources. Use `git` to get the sources:
 
@@ -65,11 +66,35 @@ where USERNAME is your account on bitbucket.
 The server will run an https server and requires valid certificates.
 To generate certificates, there are two possibilities: public server with static IP address or a private server.
 
-#### Generating certificates for a public server
+#### Generating certificates for a public server (FreeBSD)
 
-For a public server, `letsencrypt` will allow a certificate to be generated.
+```sh
+sudo pkg install py27-certbot       # FreeBSD
+```
+
+Shutdown the firewall and any server running. Then run the script to generate the certificate:
+
+```sh
+sudo service pf stop                            # disable pf firewall (FreeBSD)
+sudo certbot certonly --standalone -d www.example.com
+sudo service pf start                           # enable pf firewall
+```
+
+Certificates are saved under `/usr/local/etc/letsencrypt/live/www.example.com/`. Copy them to `aprendizations/certs` and change permissions to be readable:
 
-TODO: explain...
+```sh
+sudo cp /usr/local/etc/letsencrypt/live/www.example.com/cert.pem .
+sudo cp /usr/local/etc/letsencrypt/live/www.example.com/privkey.pem .
+chmod 400 cert.pem privkey.pem
+```
+
+Renews can be done as follows:
+
+```sh
+sudo service pf stop   # shutdown firewall
+sudo certbot renew
+sudo service pf start  # start firewall
+```
 
 Copy certificates `cert.crt` and `cert.key` to the `perguntations/certs/` directory.
 
@@ -79,7 +104,7 @@ Self-signed certificates are not certified by a recognised authority and browser
 
 ```bash
 cd perguntations/certs/
-openssl req -x509 -newkey rsa:4096 -keyout cert.key -out cert.crt -days -nodes
+openssl req -x509 -newkey rsa:4096 -keyout cert.key -out cert.crt -days 365 -nodes
 ```
 
 ## Running a demo
@@ -92,12 +117,14 @@ To run the demonstration test:
 cd WHERE/YOU/INSTALLED/perguntations
 
 # create and initialize database using one of the following methods:
-./initdb.py students.csv    # from CSV file
-./initdb.py --demo          # initialize with fake students
-./initdb.py                 # only adds the administrator account
+./initdb.py students.csv    # initialize from a CSV file
+./initdb.py --admin         # only adds the administrator account
+./initdb.py --add 123 "Asterix Gaules"  # add one student
+
+# a database file "students.db" is created
 mv students.db demo/
 
-# create directory to save the student's tests
+# create directory to save the finished tests
 mkdir demo/ans
 
 # edit test configuration and check if everything looks right
--
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