Keystone, Indicator, Umbrella, Priority, and Flagship Species

I listened to a talk about Jaguar Conservation by Dr. Hallett  and he mentioned all of the above terms and I missed several of the subsequent things he said because I was trying to make distinctions between them while he was talking. So according to WWF and Wikipedia, here are the definitions and differences:

WWF (http://wwf.panda.org/our_work/wildlife/flagship_keystone_indicator_definition/) identifies most of them pretty well: 

What is a flagship species?

• A flagship species is a species selected to act as an ambassador, icon or symbol for a defined habitat, issue, campaign or environmental cause.
• By focusing on, and achieving conservation of that species, the status of many other species which share its habitat – or are vulnerable to the same threats - may also be improved.
• Flagship species are usually relatively large, and considered to be 'charismatic' in western cultures.
• Flagship species may or may not be keystone species and may or may not be good indicators of biological process.

What is a priority species?

• The terms “flagship” and “keystone” have generally consistent definitions across the conservation community, however “priority species” is a WWF term, and is solely for the purposes of planning and simple communication.
• For WWF, a “priority species” may be either a flagship or a keystonespecies and is chosen to represent an ecoregion or region.
• A “priority species” is reflective of a key threat across that ecoregion - such that conservation of the species will contribute significantly to a broader threat mitigation outcome. It is often crucial to the economic and/or spiritual wellbeing of peoples within that ecoregion.

What is a keystone species?

• A keystone species is a species that plays an essential role in the structure, functioning or productivity of a habitat or ecosystem at a defined level (habitat, soil, seed dispersal, etc).
• Disappearance of such species may lead to significant ecosystem change or dysfunction which may have knock on effects on a broader scale. Examples include the elephant's role in maintaining habitat structure, and bats and insects in pollination.
• By focussing on keystone species, conservation actions for that species may help to preserve the structure and function of a wide range of habitats which are linked with that species during its life cycle.

What is an indicator species?

• An indicator species is a species or group of species chosen as an indicator of, or proxy for, the state of an ecosystem or of a certain process within that ecosystem.
• Examples include crayfish as indicators of freshwater quality; corals as indicators of marine processes such as siltation, seawater rise and sea temperature fluctuation; peregrine falcons as an indicator of pesticide loads; or native plants as indicators for the presence and impact of alien species.

And, then Wikipedia finishes it with What an Umbrella Species is (https://en.wikipedia.org/wiki/Umbrella_species): 

Umbrella species are species selected for making conservation-related decisions, typically because protecting these species indirectly protects the many other species that make up the ecological community of its habitat. Species conservation can be subjective because it is hard to determine the status of many species. With millions of species of concern, the identification of selected keystone species, flagship species or umbrella species makes conservation decisions easier. Umbrella species can be used to help select the locations of potential reserves, find the minimum size of these conservation areas or reserves, and to determine the composition, structure and processes of ecosystems