connect-mode

Specifies network connectivity and can be set to these values: 

• always (default) connects to remote servers when necessary.

• fast-demo connects only if the item isn’t found in the cache.

• never no connection to a remote server is ever made; returns an error if the document is not found in the cache.

cover-errors

If present and greater than 0, returns a document from the cache if the remote server is down and an up-to-date check cannot be made. The value specified is the maximum number of seconds since the last up-to-date check; if more time has elapsed, an error is returned. Using this feature involves the risk of getting stale data from the cache while the remote server is down. Setting this value to 0, or not specifying it (default) causes an error to be returned if the remote server is unavailable. 

ignore-no-cache

If present and greater than 0, a pragma: no-cache header from the remote server is ignored and the response is cached. The default value is 0. This behavior violates the HTTP standard.

ignore-no-store

If present and greater than 0, a Cache-control: no-store header from the remote server is ignored and the response is cached. The default value is 0. This behavior violates the HTTP standard.

ignore-private

If present and greater than 0, a Cache-control: private header from the remote server is ignored and the response is cached. The default value is 0. This behavior violates the HTTP standard.

ignore-reload

If present and greater than 0, a pragma: no-cache or cache-control: no-cache header from the client is ignored and the request is served from the cache. The default value is 0. This behavior violates the HTTP standard.

lm-factor

(optional)A floating-point number representing the factor used in estimating expiration time, which is how long a document might be up to date based on the time it was last modified. The time elapsed since the last modification is multiplied by this factor. The result gives the estimated time the document is likely to remain unchanged. Specifying a value of 0 turns off this function. The caching system then uses only explicit expiration information which is rarely available. Only explicit Expires HTTP headers are used. This value has no effect if max-uncheck is set to 0.

max-uncheck

(Optional) Is the maximum time in seconds allowed between consecutive up-to-date checks. If set to 0 (default), a check is made every time the document is accessed, and the lm-factor has no effect.

min-uncheck

Is the minimum time in seconds allowed between consecutive up-to-date checks of a cached document. The default value is 0. This behavior violates the HTTP standard. 

override-expire

If present and greater than 0, min-uncheck is enforced over the value of an Expires:header. The default value is 0. This behavior violates the HTTP standard.

override-lastmod

If present and greater than 0, min-uncheck is enforced over the value of a Last-modified header. The default value is 0. This behavior violates the HTTP standard.

reload-into-ims

If present and greater than 0, reload request from clients are converted into conditional GET requests with an If-modified-since header. The default value is 1. This behavior violates the HTTP standard.

require-expires

If present and greater than 0, a response without an Expires header will not be cached. The default value is 1. This behavior violates the HTTP standard.

term-percent

Indicates that the server should keep retrieving data if more than the specified percentage of the document has already been retrieved. 

without-lastmod

If present and greater than 0, the absence of a Last-modified header is ignored and the response cached. The default value is 0. This behavior violates the HTTP standard.