Using the excellent Charles web proxy debugger I noticed that there are no caching headers on some JS and CSS and images

For example

http://localhost:8090/jira/s/420/1/_/styles/combined-printable.css 200 GET localhost:8090 /jira/s/420/1/_/styles/combined-printable.css 978 bytes Complete 9 ms
http://localhost:8090/jira/s/420/1/_/styles/combined.css 200 GET localhost:8090 /jira/s/420/1/_/styles/combined.css 63.10 KB Complete 14 ms
http://localhost:8090/jira/s/420/1/23283/_/styles/global.css 200 GET localhost:8090 /jira/s/420/1/23283/_/styles/global.css 2.49 KB Complete 6 ms
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:jquery-all/com.atlassian.auiplugin:jquery-all.js 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:jquery-all/com.atlassian.auiplugin:jquery-all.js 293.25 KB Complete 17 ms
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/com.atlassian.auiplugin:ajs.css 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/com.atlassian.auiplugin:ajs.css 14.04 KB Complete 5 ms
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/com.atlassian.auiplugin:ajs.js 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/com.atlassian.auiplugin:ajs.js 67.91 KB Complete 6 ms
http://localhost:8090/jira/s/420/1/1.0/_/download/batch/jira.webresources:jira-global/jira.webresources:jira-global.js 200 GET localhost:8090 /jira/s/420/1/1.0/_/download/batch/jira.webresources:jira-global/jira.webresources:jira-global.js 16.04 KB Complete 6 ms
http://localhost:8090/jira/s/420/1/1.0/_/download/batch/jira.webresources:jira-global/jira.webresources:jira-global.css 200 GET localhost:8090 /jira/s/420/1/1.0/_/download/batch/jira.webresources:jira-global/jira.webresources:jira-global.css 4.38 KB Complete 4 ms
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/rt.png 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/rt.png 1.21 KB Complete 4 ms 16x17
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/l.png 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/l.png 1.11 KB Complete 5 ms 16x16
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/lt.png 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/lt.png 1.18 KB Complete 6 ms 16x17
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/r.png 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/r.png 1.11 KB Complete 4 ms 16x16
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/lb.png 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/lb.png 1.34 KB Complete 4 ms 29x29
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/rb.png 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/rb.png 1.41 KB Complete 4 ms 29x29
http://localhost:8090/jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/b.png 200 GET localhost:8090 /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:ajs/images/shadow/b.png 1.14 KB Complete 4 ms 16x29

Come down when not expected to :

And say for :

GET /jira/s/420/1/1.1.1/_/download/batch/com.atlassian.auiplugin:jquery-all/com.atlassian.auiplugin:jquery-all.js HTTP/1.1

here are the response headers

HTTP/1.1 200 OK
Server Apache-Coyote/1.1
Content-Type application/x-javascript;charset=UTF-8
Transfer-Encoding chunked
Date Thu, 21 May 2009 23:31:19 GMT

We cannot SHIP without proper caching