diff --git a/README.md b/README.md
index 57e4a12..29e6e18 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # kurijn.github.io
 
 $ curl -I https://kurijn.github.io  
-HTTP/2 200 → HTTP/2 (or higher) is very desirable.  
+HTTP/2 200 → HTTP/2 (or higher) is very desirable for using RDF data for reliability and speed.  
 server: GitHub.com  
 content-type: text/html; charset=utf-8  → we have an html file (containing RDFa triples as Turtle)  
 permissions-policy: interest-cohort=()  
@@ -9,18 +9,18 @@ last-modified: Wed, 06 Mar 2024 01:36:34 GMT
 access-control-allow-origin: *  → This header indicates that the code on this domain can be executed in a browser from within another domain, which is a desirable feature to make the RDF data available on other domains.  
 strict-transport-security: max-age=31556952  
 etag: "65e7c8a2-c1d" → the ETag header is a unique value generated by the server, which the client can use to verify if the cached resource hasn't changed on the server (if so the server replies with status code 304).  
-expires: Wed, 06 Mar 2024 02:09:25 GMT  
-cache-control: max-age=600 → this is the maximum allowed age (in seconds - so, 10 minutes here) to use the cached resource.  
+expires: Wed, 06 Mar 2024 02:09:25 GMT   → The expiration date-time of the cached resource.
+cache-control: max-age=600 → this is the maximum allowed age (in seconds - so, 10 minutes here) to use the cached resource.
 x-proxy-cache: MISS  
 x-github-request-id: EDBA:331E65:47E307:495F5F:65E7CDFD  
 accept-ranges: bytes  
 date: Wed, 06 Mar 2024 01:59:25 GMT  
-via: 1.1 varnish  
-age: 0  
+via: 1.1 varnish  → Varnish is used as HTTP accelerator (provinding cache and compression) for content-heavy dynamic web sites, which is useful for RDF data.
+age: 0    → age (in seconds) at the time of request (0 means we received the original server copy).
 x-served-by: cache-bru1480044-BRU  
 x-cache: MISS  
 x-cache-hits: 0  
 x-timer: S1709690366.684412,VS0,VE110  
-vary: Accept-Encoding  
+vary: Accept-Encoding   → The vary header needs to be set when a caching based on expiration or ETag header is set. Here we see that "Accept-Encoding" is another header that can change the cache key.
 x-fastly-request-id: 180981ddd2b4a32f0ad6bac30f35f3e242b2690c  
 content-length: 3101