| block_authorship | An authorship block (prepared-by line + metadata) |
| block_flow_diagram | A model-development flow-diagram block |
| block_image | A block that embeds a raster image |
| block_keep | Keep a group of blocks together on one page (atomic) |
| block_matrix | A wide-matrix block that groups columns to fit the page width |
| block_para | A word-wrapped paragraph block |
| block_plot | A block that draws a base-R plot into a reserved region |
| block_pre | A preformatted (monospace) block for capture.output() dumps |
| block_rule | A horizontal rule spanning the frame width |
| block_signature | A signature / approval block (visible lines + optional interactive fields) |
| block_spacer | A vertical spacer block |
| block_table | A table block with measured column widths and automatic page splitting |
| flow_add | Add a single block imperatively |
| flow_run | Run a sequence of blocks through the flow engine |
| frame_set | Set the content frame (and reset the cursor to its top) |
| remaining | Vertical space remaining in the current frame (points) |
| running | Set the running header / footer |
| running_footer | Set the running header / footer |
| running_header | Set the running header / footer |
| sp_add_sig_fields | Add interactive Acrobat signature fields to a finished PDF |
| sp_close | Close the document (flush the PDF) |
| sp_figure_page | Draw a full-page multi-panel figure (outside the flow engine) |
| sp_height | Line height (vertical advance) in points |
| sp_new | Open a new simPDF document |
| sp_overlaps | Return overlapping text bounding-box pairs recorded while tracing |
| sp_page | Start a new page |
| sp_trace | Turn bounding-box tracing on for no-overlap checks |
| sp_width | Measure text width in points |