Merge branch 'cert-update' into 'master'

Update obtaining-login-credentials.md

See merge request sccs/docs.it4i.cz!404

docs.it4i/general/obtaining-login-credentials/obtaining-login-credentials.md

@@ -10,7 +10,7 @@ If you are not eligible for an e-INFRA CZ account, contact the [IT4I support][a]
 1. Attach the AUP file
 1. Your preferred username (length is limited between 4 and 7 letters)<br>The preferred username must associate with your first and last name or be otherwise derived from it. Note that the system will automatically add the `it4i-` prefix to your username.
 1. Public part of your SSH key<br>If you don't provide it in the ticket, you must [add it manually][s] after your account is created.
-1. All information above should be provided by email, the email must be digitally signed by a CA authority. Read more on [digital signatures][4] below. If you do not have such a digital signature, you can choose an [Alternative way to personal certificate][3]; a scan of photo ID (personal ID or passport or driver license) is required.
+1. All information above should be provided by email that is **digitally signed by a CA authority**. Read more on [digital signatures][4] below. If you do not have such a digital signature, you can choose an [Alternative way to personal certificate][3]; a scan of photo ID (personal ID or passport or driver license) is required.
 
 Example (except the subject line, which must be in English, you may use Czech or Slovak language for communication with us):
 
@@ -39,7 +39,7 @@ The clusters are accessed by the [private key][5] and username. Username and pas
 
 ## Certificates for Digital Signatures
 
-We accept personal certificates issued by any widely respected certification authority (CA). This includes certificates by CAs organized in [International Grid Trust Federation][f], its European branch [EUGridPMA][g] and its member organizations, e.g. the [CESNET certification authority][h]. The Czech _"Qualified certificate" (Kvalifikovaný certifikát)_ provided by [PostSignum][i] or [I.CA][j], which is used in electronic contact with Czech authorities, is accepted as well.
+We accept personal certificates issued by any widely respected certification authority (CA). This includes certificates by CAs organized in [International Grid Trust Federation][f], its European branch [EUGridPMA][g] and its member organizations, e.g. the [CESNET certification authority][h]. The Czech _"Qualified certificate" (Kvalifikovaný certifikát)_ provided by [PostSignum][i] or [I.CA][j], which is used in electronic contact with Czech authorities, is accepted as well. **In general, we accept certificates issued by any trusted CA that ensures unambiguous identification of the user.**
 
 Certificate generation process for academic purposes, utilizing the CESNET certification authority, is well described here:
 
@@ -50,13 +50,19 @@ Certificate generation process for academic purposes, utilizing the CESNET certi
 
 If you are not able to obtain the certificate from any of the respected certification authorities, follow the Alternative Way below.
 
-A FAQ about certificates can be found here: [Certificates FAQ][7].
+FAQ about certificates can be found here: [Certificates FAQ][7].
 
 ## Alternative Way to Personal Certificate
 
 !!! important
-    Follow these steps **only** if you cannot obtain your certificate in a standard way.
-    If you choose this procedure, **you must attach a scan of your photo ID** (personal ID, passport, or driver's license) when applying for login credentials.
+    Choose this alternative **only** if you cannot obtain your certificate in a standard way.
+    Note that in this case **you must attach a scan of your photo ID** (personal ID, passport, or driver's license) when applying for login credentials.
+
+An alternative to personal certificate is an S/MIME certificate allowing secure email communication,
+e.g. providing sensitive information such as ID scan or user login/password.
+
+
+The following example is for Actalis free S/MIME certificate, but you can choose your preferred CA.
 
 * Go to the [Actalis Free Email Certificate][l] request form.
 * Follow the instructions: fill out the form, accept the terms and conditions, and submit the request.