Usage:
rlabel [ offset default | x,y,z ] atom-spec

Usage:
~rlabel atom-spec

Rlabel displays labels for residues with any atom in atom-spec. ~Rlabel removes residue labels. The default label contents are residue name and specifier, but custom residue labels can be defined using labelopt or the custom residue labeling dialog. Label font, size, and whether to draw labels in front regardless of their Z-offsets (default true) can be set in the Labels preferences. The command label shows atom labels. See also: color, 2dlabels, the Actions menu

The offset keyword allows specifying an absolute offset or a return to the default behavior, which depends on the method of residue label positioning. The word default can be truncated. An absolute offset is specified by three comma-separated values x,y,z representing distances along the X-, Y-, and Z-axes in the laboratory coordinate system:

• the X-axis is horizontal in the plane of the screen, increasing to the right
• the Y-axis is vertical in the plane of the screen, increasing upward
• the Z-axis is perpendicular to the screen, increasing outward (toward the viewer)

The method of residue label positioning can be set in the molecule model attributes panel or with the command setattr. Residue label position can be based on:

• the centroid of the displayed atoms in the residue (default method; default offset 0,0,1)
• the centroid of the displayed backbone atoms (mainchain atoms) in the residue, and for residues without such atoms, the centroid of the displayed atoms in the residue (default offset 0.5,0,0.5)
• the residue primary atom, generally CA in an amino acid, C5' in a nucleotide, the first nonhydrogen atom in residues of other types (default offset (display_radius + 0.2),0,0.5, automatically adjusted along with display style)