16. Tables

16.1 Labeling and presentation of tables

Tables provide a clear and concise way of presenting large amounts of data in a small space. The example draft in Annex B shows examples of properly formatted tables.

Working groups shall obtain permission to use any table from another source, including from a manufacturer, prior to using it in a draft standard (see Clause 5).

Formal tables should be given a number and a concise title, and they should be cited in the text with the word Table followed by the number. (See 16.2 for information on the numbering of tables.) Tables should be boxed, ruled and organized to fit on a single page. with the term, “Table” and the table number, followed by an em dash and the table title, all on one line, centered above the top border of the table, as follows: “Table 1—Title”. If a table carries over to more than one page, complete column headings should be repeated at the top of successive pages. The table number and title, with the term, “continued,” in parentheses and in italics, should be repeated and centered above the top border of the table on the successive pages, as follows: “Table 1—Title (continued).”

16.2 Numbering and capitalization in tables

Tables should be consecutively numbered in a separate series and in the order of their reference in the text (e.g., Table 1, Table 2, Table 3). Hyphenated numbers should not be used except in standards of considerable length. In the latter case, it is appropriate to label the first table in a clause with the number 1, preceded by the clause number (e.g., Table 6-1, Table 6-2).

Tables included in annexes should also carry the identifying letter of the annex in which they appear, followed by a period. For example, the first table in Annex B should be identified as Table B.1.

Tables should be referenced in the text by the word, “Table” and their number only (e.g., “see Table 1”). If referring to two or more tables in the same sentence, each should be named separately. For example, use “see Table 1, Table 2, and Table 3,” instead of “see Tables 1 through 3.”

Only the initial letter of the first word and proper nouns should be capitalized in

• Table titles
• Column and line headings in tables (see Table B.1 in Annex B)

16.3 Presentation of data and table format

16.3.1 Units of measure

Units of measure shall always be provided in the title (in parentheses); or preceded by a solidus in the column headings [e.g., for volts either E(V) or E/V would be acceptable]; or in a NOTE. The same units of measure shall be used throughout each column; ohms shall not be combined with megohms, millimeters with centimeters, or seconds with minutes. To save space, abbreviations and letter symbols should be used in column and line headings wherever possible. (See IEEE Std 260.1 and other standards referenced in Clause 2 for the appropriate abbreviations and symbols for use in standards.)

16.3.2 Numerical values

Digits should be separated into groups of three, counting from the decimal point toward the left and right. The groups should be separated by a space, and not a comma, period, or dash. If the magnitude of the number is less than one, the decimal point should be preceded by a zero. In numbers of four digits, the space is not necessary, unless four-digit numbers are grouped in a column with numbers of five digits or more.

Examples:

73 722   7372   0.133 47

All numbers should be aligned at the decimal point, where appropriate. Only as many significant digits should be used as the precision of data justifies. Decimal fractions should be used in tabulations unless fractions are commonly used in the field.

Common fractions and decimal fractions shall not be combined in the same table. An em dash (—) should be used to indicate the lack of data for a particular cell in a table.

16.4 Notes and footnotes to tables

Subclause 6.4 of the IEEE SA Standards Board Operations Manual defines which parts of a standard are normative and which parts of a standard are informative.

A table note (a note to a table) is informative. A table footnote is normative. This distinction should be kept in mind when determining whether information should go in a table note or a table footnote.

A table note should be set immediately following the table to which it belongs, enclosed within the boxed table, above the bottom border of the table. The text in the table note shall not contain mandatory requirements. Also, important information on safety, health, or the environment related to the table shall not be included in table notes.

Table notes should appear in the following order:

1. General notes and specific notes. General notes apply to the entire table and should be introduced by “NOTE—” set in all, uppercase letters. Specific notes should refer to specific material or parts of the table and should also be introduced by “NOTE—” set in all, uppercase letters. Multiple notes in sequence should be numbered “NOTE 1—”, “NOTE 2—”, etc.

2. Crediting source. Use either of the following credit lines:

   Reprinted with permission from… (Use when data is derived from another source from which permission to reproduce material has been obtained.)

   Source: (Use when data is derived from another IEEE standard.)

A table footnote always contains normative information. A table footnote should be set outside of the boxed table to which it belongs, immediately below the bottom border. The text in the footnote may contain mandatory requirements. Any important information on safety, health, or the environment related to the table shall be included in the footnote.

A table footnote should be marked with lowercase letters starting with “a” for each table.

16.5 Informal tables

Simple tabulations that are not referred to outside of the subclause in which they appear may be organized into short informal tables that do not exceed five lines in depth. However, it is recommended that all tables be numbered and titled, if possible. See the example draft in Annex B for an example of an informal table.