Any string literal that is intended to be displayed on the diagram can be followed by zero or more of the following keywords, in any order:

Attributes "above" and "below"

The "above" and "below" keywords control the location of the text above or below the center point of the object with which the text is associated. If there is just one text on the object and the "above" and "below" keywords are omitted, the text is placed directly over the center of the object. This causes the text to appear in the middle of lines:

on the line
  line "on the line" wid 150%

So if there is just a single text label on a line, you probably want to include either the "above" or "below" keyword.

above below
  line "above" above; move; line "below" below

If there are two texts on the object, they straddle the center point above and below, even without the use of the "above" and "below" keywords:

text without "above" text without "below"
  line wid 300% "text without \"above\"" "text without \"below\""

The "above" and "below" attributes do not stack or accumulate. Each "above" or "below" overrides any previous "above" or "below" for the same text.

If there are multiple texts and all are marked "above" or "below", then all are placed above or below the center point, in order of appearance.

first above second above first below second below
  line width 200% "first above" above "second above" above
  line same "first below" below "second below" below

Attributes "ljust" and "rjust"

As the "above" and "below" keywords control up and down positioning of the text, so the "ljust" and "rjust" keywords control left and right positioning.

For a line, the "ljust" means that the left side of the text is flush against the center point of the line. And "rjust" means that the right side of the text is flush against the center point of the line. (In the following diagram, the red dot is at the center of the line.)

ljust rjust
   line wid 200% "ljust" ljust above "rjust" rjust below
   dot color red at previous.c

For a block object, "ljust" shifts the text to be left justified against the left edge of the block (with a small margin) and "rjust" puts the text against the right side of the object (with the same margin).

ljust longer line even longer line rjust longer line even longer line
   box "ljust" ljust "longer line" ljust "even longer line" ljust fit
   box "rjust" rjust "longer line" rjust "even longer line" rjust fit

The behavior of "ljust" and "rjust" for block objects in Pikchr differs from legacy PIC. In PIC, text is always justified around the center point, as in lines. But this means there is no easy way to left justify multiple lines of text within a "box" or "file", and so the behavior was changed for Pikchr.

Pikchr allows two texts to fill the same vertical slot if one is "ljust" and the other is "rjust".

above-ljust above-rjust centered below-ljust below-rjust
  box wid 300% \
     "above-ljust" above ljust \
     "above-rjust" above rjust \
     "centered" center \
     "below-ljust" below ljust \
     "below-rjust" below rjust

Attribute "center"

The "center" attribute cancels all prior "above", "below", "ljust", and "rjust" attributes for the current text.

Attributes "bold" and "italic"

The "bold" and "italic" attributes cause the text to use a bold or an italic font. Fonts can be both bold and italic at the same time.

bold italic bold-italic
  box "bold" bold "italic" italic "bold-italic" bold italic fit

Monospace Font Family

The "mono" or "monospace" attributes cause the text object to use a monospace font.

  box "monospace" monospace fit

Attribute "aligned"

The "aligned" attribute causes text associated with a straight line to be rotated to align with that line.

aligned aligned aligned
  arrow go 150% heading 30 "aligned" aligned above
  move to 1cm east of previous.end
  arrow go 150% heading 170 "aligned" aligned above
  move to 1cm east of previous.end
  arrow go 150% north "aligned" aligned above

To display rotated text not associated with a line attach the text to a line that is marked "invisible"

rotated text
  box ht 200% wid 50%
  line invis from previous.s to previous.n "rotated text" aligned

Attributes "big" and "small"

The "big" and "small" attributes cause the text to be a little larger or a little smaller, respectively. Two "big" attributes cause the text to be larger still, as do two "small" attributes. But the text size does not increase or decrease beyond two "big" or "small" keywords.

small small small (normal) big big big
  box "small small" small small "small" small \
    "(normal)" italic \
    "big" big "big big" big big ht 200%

A "big" keyword cancels any prior "small" keywords on the same text, and a "small" keyword cancels any prior "big" keywords.