Short solid lines drawn perpendicular near but not touching the ends of the dimension lines they relate to.

The short solid lines you are referring to are known as "extension lines" in technical drawings and drafting. These lines extend from the end of a dimension line to indicate the points between which the dimension is applied. They help in clarifying the precise measurement provided by the dimension line without cluttering the drawing itself.

Characteristics of Extension Lines:

1. Purpose: Extension lines define the limits of the dimension by indicating the specific points for which the measurement is applicable.
2. Positioning: They are drawn perpendicular to the dimension lines and are usually placed close to—but not touching—the object or feature being dimensioned.
3. Style: Extension lines are typically drawn as solid lines to differentiate them from other types of lines in a drawing, such as hidden lines or centerlines.

Using extension lines is essential for clear communication of dimensions in engineering and architectural drawings to ensure that all dimensions are easily readable and not ambiguous.