I found an example here that is a lot more detailed than the text you are quoting from:

http://tools.ietf.org/html/rfc2527

Section 3.2 and 3.3. This seemed particularly relevant from Section 3.3.1 -

When processing a certification path, a certificate policy that is acceptable to the certificate-using application must be present in every certificate in the path, i.e., in CA-certificates as well as end entity certificates.

Reading it, it sounds like they may not be a mathematically perfect subset (the ones I've seen are usually written in English, anyway), but the policies of the entire path relate when an application chooses to trust a given end entity.

In practice, I believe a common example is to have the main CA chain reference a given policy that is fairly general, but then specialized CAs and their issues certificates may reference a more restrictive policy that fits within the generalized one, for a specialized usage.

I found an example here that is a lot more detailed than the text you are quoting from:

https://www.rfc-editor.org/rfc/rfc2527

Section 3.2 and 3.3. This seemed particularly relevant from Section 3.3.1 -

When processing a certification path, a certificate policy that is acceptable to the certificate-using application must be present in every certificate in the path, i.e., in CA-certificates as well as end entity certificates.

Reading it, it sounds like they may not be a mathematically perfect subset (the ones I've seen are usually written in English, anyway), but the policies of the entire path relate when an application chooses to trust a given end entity.

In practice, I believe a common example is to have the main CA chain reference a given policy that is fairly general, but then specialized CAs and their issues certificates may reference a more restrictive policy that fits within the generalized one, for a specialized usage.

I found an example here that is alot more detailed than the text you are quoting from:

http://tools.ietf.org/html/rfc2527

Section 3.2 and 3.3. This seemed particularly relevant from Section 3.3.1 -

When processing a certification path, a certificate policy that is acceptable to the certificate-using application must be present in every certificate in the path, i.e., in CA-certificates as well as end entity certificates.

Reading it, it sounds like they may not be a mathematically perfect subset (the ones I've seen are usually written in English, anyway), but the policies of the entire path relate when an application chooses to trust a given end entity.

In practice, I believe a common example is to have the main CA chain reference a given policy that is fairly general, but then specialized CAs and their issues certificates may reference a more restrictive policy that fits within the generalized one, for a specialized usage.

I found an example here that is a lot more detailed than the text you are quoting from:

http://tools.ietf.org/html/rfc2527

Section 3.2 and 3.3. This seemed particularly relevant from Section 3.3.1 -

When processing a certification path, a certificate policy that is acceptable to the certificate-using application must be present in every certificate in the path, i.e., in CA-certificates as well as end entity certificates.

Reading it, it sounds like they may not be a mathematically perfect subset (the ones I've seen are usually written in English, anyway), but the policies of the entire path relate when an application chooses to trust a given end entity.

In practice, I believe a common example is to have the main CA chain reference a given policy that is fairly general, but then specialized CAs and their issues certificates may reference a more restrictive policy that fits within the generalized one, for a specialized usage.