Suggestions for coseoul
The following packages have something in common with the package coseoul. The packages are ordered in decreasing similarity.
- alnumsec: Alphanumeric section numbering
 - anonchap: Make chapters be typeset like sections
 - alphanum: Sectioning commands for jura
 - chbibref: Change the Bibliography/References title
 - fncychap: Seven predefined chapter heading styles
 - outliner: Change section levels easily
 - section: Modifying section commands in LaTeX
 - sectsty: Control sectional headers
 - nccsect: A re-implementation of sections, captions and tocs
 - topsection: An un-numbered top level section
 - secdot: Section numbers with trailing dots
 - crumbs: Add a Navigation Path to the page header
 - bsheaders: Double-ruled chapter heading style
 - quotchap: Decorative chapter headings
 - standardsectioning: Define sectioning commands identical to the standard classes
 - modular: Relative section headings for modular documents
 - tocvsec2: Section numbering and table of contents control
 - texilikechaps: Format chapters with a texi-like format
 - varsects: A simple package for controlling headings
 - serbianpart: Redefines \thepart to be used in Roman lettered Serbian
 - sectionbreak: LaTeX support for section breaks
 - appendix: Extra control of appendices
 - secnum: A macro to format section numbering intuitively
 - uvaletter: Unofficial letterhead template for the University of Amsterdam
 - tramlines: A package for creating tramlines (lines above and below a title used by lawyers in the UK)
 - titlesec: Select alternative section titles
 - notoccite: Prevent trouble from citations in table of contents, etc.
 - indentfirst: Indent first paragraph after section header
 - fancychapters: Chapters with quotations
 - sshdbk10: Sans headers in book style
 - sober: Makes appearance of standard styles more “sober”