Many department and specialty stores have enlarged their departments for the shorter woman. However, some stores specialize in clothes for shorter woman. Among them:

Lane Bryant--Well-known for "large-size" clothes, has launched "LB for Short," a mail-order division of Lane Bryant. Misses petite sizes 2-16; junior petite sizes 3-13. From LB for Short, 2300 Southeastern Ave., Indianapolis, Ind. 46201.

Catalogue samples: Evan Picone Petites jacket and skirt suit in poly/rayon/silk, $160; Liz Claiborne Petites textured poly/rayon fitted jacket, $110; matching skirt, $55; ruffle-collar blouse, $50; "little black dress" for evening, $46.

Piaffe, 1323 Connecticut Ave. NW--Just opened one of the best stores in the area, offering clothes exclusively for the petite woman, sizes 0-8. Petite range from some top designers including sportswear from Liz Claiborne Petites, khaki canvas bottoms $35 to $38; Alpha Cubic plaid cotton separates, $70 to $80; Lon Sabella evening separates in black or khaki silk, $125 to $165; Jones of New York Petite classic rayon/polyester separates in primary colors, $50 to $105. Lingerie from $18 to $28, and Diane Von Furstenberg small pantyhose, $4.50. Free alterations.

Small Stuff, Tysons Corner Mall--Mostly updated sportswear in the moderate price range, made for the chain in sizes 0-9. Includes quilted jackets, $30; cotton culottes, $18; Derriere jeans, $18 to $30. Accessories include very well priced bags and concho belts in small sizes, $7. For Men

For the short man tired of shopping in the boys department: shorter-length jackets and sleeves, pants with a different rise.

Jos. A. Bank Clothiers, 1118 19th St. NW (also in Falls Church and Rockville)--Good selection for smaller-sized men from this manufacturer of traditional menswear. Suits, jackets and slacks, sizes 37 Short to 44 Short. Wool and wool-blend suits, $145-$200; tuxedos, $175-$185; sport coats, $85-$150; slacks, $22.50 (khaki/cotton) to $52.50 for wool; wool topcoats, $175-$345; belts (30-inch waist the smallest); shirts (beginning with size 14 1/2) $17-$28.50.

Steven-Windsor, 7 Corners Center, Falls Church--Special "Short Man's Shop" within the regular menswear store, sizes from 34 Extra Short to 44 Short, including "Portly Short." Among brand-name suits for short men: Yves St. Laurent, John Weitz, Giorgio Sant'Angelo and Kingsridge. Suits range from $125-$300; sport coats, $125-$300; slacks in sizes 28-44 Short, $30-$55; good selection of London Fog rainwear, $110-$135; shirts, size 14/30 and up, $22-$27.50; smaller sized socks (9-11) from Burlington, $2.75; ties, four inches shorter than normal, $7.50-$15; belts size 28-44, $8.50-$15; short-fingered leather gloves by David Hays, $30. Cardigan and pullover sweaters with shorter body and sleeves, $30-$50. Good selection of sport shirts, $25, and jeans, $27.50).

Hahn's Shoe Store across from Steven-Windsor in 7 Corners--Now has small sizes (6, 6 1/2 and 7) in men's shoes. Florsheim's basic moc-toed soft leather loafers, $61-$79; Florsheim wing tips, $96; Bass plain and tassel loafers, $62-$63; Hush Puppies standard lace-ups, $29.