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Glossary for Tree of Life Contributors

Accessory Page
Accessory pages, formerly called lichen pages, are pages that are attached to either branch or leaf pages of the Tree, but they are not themselves part of the Tree structure. They do not provide the primary information about the groups of organisms (this is provided on the branch or leaf pages), but instead contain additional information, perhaps including more detailed descriptions of structure, discussion of phylogenetic relationships, more pictures, identification keys, etc. While links to many additional pages can be made from a Tree branch or leaf, only those linked pages that are specially designated and included in the Tree of Life's index are considered accessory pages. See Introduction to Tree of Life Pages for an explanation of the different page types on the Tree of Life, and Design of an Accessory Page for a detailed description of the elements of an accessory page.

Authors are the people who write Tree of Life pages. Please see the page on Expectations of Tree of Life Authors for more information.

Branch Page
Branch pages are all of the Tree of Life pages that have (or will eventually have) Tree pages descended from them. Most pages on the Tree of Life are branch pages, but there are also Leaf pages and Accessory Pages. See Introduction to Tree of Life Pages for an explanation of the different page types on the Tree of Life, and Design of a Branch Page for a detailed description of the elements of a branch page.

Software on the client computer that requests information from servers and displays it to the user. Popular browsers include Netscape, Mozilla, Safari, and Internet Explorer.

A computer that is requesting information from a server.

Containing Group
The containing group is a larger group that includes the taxon represented on a given Tree of Life page. The Tree of Life page for the (immediately) containing group shows the current group as one of the terminal taxa in its tree or taxon list. See Introduction to Tree of Life Pages and Design of a Branch Page for more detailed explanations.

Coordinators are Tree of Life authors who oversee the development of the pages descending from their clade. Coordinators choose appropriate authors for subgroups and serve as associate editors for this particular section of the Tree. See Coordinators for a more detailed explanation.

The correpondent is the Tree of Life author who agrees to answer inquiries by readers of a Tree of Life page.

Descendant Taxon
Descendant taxa are the terminal taxa displayed on the tree at the top of a Tree of Life branch page. The names of these taxa constitute links to the Tree of Life pages of the groups descending from the current group.

GIF is a widely used compression format for image files developed by CompuServe. The acronym stands for "Graphic Interchange Format". Since there is considerable loss of color depth in GIF compression, we recommend that Tree of Life authors use this format only for line drawings and diagrams requiring only a few different colors (i.e. no graded shadings); photographs should always be saved in JPEG format.

HTML file
HyperText Markup Language (HTML) is the universal language used to produce pages on the World Wide Web. HTML documents are plain-text files containing the text which is to be shown on a World Wide Web page along with a set of instructions (HTML codes) on how the text is to be displayed by a World Wide Web browser. Furthermore, there may be instructions about the display of pictures, about links to other World Wide Web pages, etc.

Index Page
For some large groups that are distributed across many different Tree of Life pages, it may be useful to have an index page with links to the most important taxa. For example, it takes meandering through several pages to get to some of the insect orders. So in order to facilitate navigation to certain lineages, there is a link to an index page on each of the main insect pages that takes you to an alphabetical list of orders. This would allow people to quickly find a group without having to search through the Tree.

JPEG is a popular file compression format which allows the storage of high quality images in relatively small files. The acronym stands for "Joint Photographic Expert Group". We recommend that Tree of Life authors use JPEG files for all their photographs and any art work that requires high color depth. JPEG compression does not work especially well with hard edges and lines in graphics images. Simple line drawings and pictures with transparent areas should be compressed into GIF rather than JPEG files.

Leaf Page
Leaf pages are the Tree of Life pages presenting information about individual species. They are the terminal pages on the Tree, and are attached to apical branches. See Introduction to Tree of Life Pages for an explanation of the different page types on the Tree of Life, and Design of a Leaf Page for a detailed description of the elements of a leaf page.

Lichen Page
see Accessory Page.

A link is a reference from some point in one HTML document to some point in another document or to another place in the same document. A browser usually displays a link in some distinguishing way, e.g. in a different color. When the reader clicks on the highlighted text or graphic element, the browser will display the target of the link.

A computer that shares files with other computers connected to it via a network. Tree of Life pages are HTML files that are created from information in the ToL Database. The ToL server then makes these files available to people who can access them with a computer through the World Wide Web.

Title Illustration
At the top of each Tree of Life Title Illustrations page contains a detailed treatment of the requirements and recommendations for Tree of Life title illustrations.
TreeGrow is a computer program that allows Tree of Life authors to edit data in the Tree of Life database. Refer to the pages on Using TreeGrow for a detailed description of what TreeGrow does and for information on how you can acquire the program.
Treehouses are a special kind of accessory page that is designed for children or the young at heart. Our goal is to have treehouses sprinkled throughout the Tree, as authors' time and resources permit. Currently, there is one treehouse available on the tree, the Beetle Treehouse.

Trunk Page
Trunk pages are those branch pages that comprise the path from the root of the Tree up into prominent groups (e.g. into mammals, flowering plants, insects).

This is the abbreviation for "Uniform Resource Locator", the addressing system used on the World Wide Web. The URL contains information about the method of access (e.g. whether it is an HTTP file, or FTP file, etc.). Refer to HTML for ToL Pages for further information.

World Wide Web.

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