Flickr API results cacheable?

When using the Flickr API for getting informations on a photo, I get a result looking like this:

<photo id="2733" secret="123456" server="12" isfavorite="0" license="3" rotation="90" originalsecret="1bc09ce34a" originalformat="png">
  <owner nsid="12037949754@N01" username="Bees" realname="Cal Henderson" location="Bedford, UK" />
  <title>orford_castle_taster</title>
  <description>hello!</description>
  [...]
</photo>

I am planning of caching the results in a database, however I am wondering if some photo informations might not be cacheable on the long term, especially the properties that are used for building URLs (secret, server, farm-id...).

Solution

Discussions in the Flickr API group would suggest that developers are successfully caching results. I found this post (it's a bit old), which uses PHP, as well as this more recent thread.