The descriptions of keywords and their associated input are now described in alphabetical order. Several formatting conventions are used to help the user interpret the input requirements. Keywords are always capitalized and bold. Words in bold must be included literally when creating input data sets (although upper and lower case are interchangeable and optional spellings may be permitted). "Identifiers" are additional keywords that apply only within a given keyword data block; they can be described as sub-keywords. " Temperature" is an identifier for SOLUTION input. Each identifier may have two forms: (1) the identifier word spelled exactly (for example, " temperature"), or (2) a hyphen followed by a sufficient number of characters to define the identifier uniquely (for example, -t for temperature). The form with the hyphen is recommended. Words in italics are input values that are variable and depend on user selection of appropriate values. Items in brackets ([ ]) are optional input fields. Mutually exclusive input fields are enclosed in parentheses and separated by the word "or". In general, the optional fields in a line must be entered in the specified order and it is sometimes possible to omit intervening fields. For clarity, commas are used to delimit input fields in the explanations of data input; however, commas are not allowed in the input data file; only white space (spaces and tabs) may be used to delimit fields in input data sets. Where applicable, default values for input fields are stated.