Thanks @mlinksva. Sorry my English (is not an usual language for me), I will try to explain… But at the risk of too much explanations (less is more
The “balance” is a compensation: the Berne Convention imposes some “default rules”, with no choice, except with (at the expense of) some transaction cost. The standardization of the “opposite of Berne” licenses, in the last years, as the CC0, and other popular options like GPL, CC-BY, etc. are now the low-cost choices. This “balance” is an important context to describe the main and most popular license clauses (BY, NC, ND, and others in Berne or in opposition to Berne clauses).
About formal definition of “implied license” (or implicit license), I think there are no international agreement, so, it is an informal concept… But is sufficient as label of “opposite of explicit license”. A link to CC-BY in a webpage, an attachment in a Gutenberg’s book, or a symbol “© Crown copyright” (OGL-UK) in a PDF law of legislation.gov.uk, all these are examples of “explicit licenses”… There are a license when it is not explicit? Yes it is possible (!). All 7.9 million of documents listed here by LexML have an implied license, and it is materialized here.
If this notion of “implied license” makes sense, we can say that the “automatic protection” is an implied license (!)… And will be a good idea to express (to materialize in a license format), as we trying here.
@Stephen, to say “open by default” is possible, since the government “say” something permitted by Berne, as Article 2.4, and on a document that have force of law, like the evidences cited here.
PS: of course, usually, “explicit licenses” are better than “implied licenses”.
About “to publish using CC-BY” in the government, is a good practice and have some good references as UK (that use OGL-UK=CC-BY), but for public sector the usual recommendation is CC0 or a CC0 variation. Example: the “BY clause” in a map causes more cost tham CC0, for practical work in the openstreetmap community, and map features reuse and distribution.