TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The component of the device comprises at least one optically uniaxial films selected from an A-plate, C-plate, negative C-plate or O-plate, a twisted optical retarder, twisted quarter wave foil (QWF), optically biaxial film, achromatic retarder, achromatic QWF or half wave foil (HWF), film having a cholesteric, smectic, nematic or blue phase, film having homeotropic, splayed, tilted, planar or blue-phase alignment, which is uniformly oriented or exhibits a pattern of different orientations. The component of the device is an optical compensator for viewing angle enhancement, brightness enhancement element, or achromatic retarder. The component of the device is a retarding component in an optoelectronic device requiring similar phase shift at multiple wavelengths, including combined compact disc (CD)/digital versatile disc (DVD)/high definition (HD)-DVD/Blu-Ray, reading and/or writing and/or re-writing data storage systems, achromatic retarder for optical devices including cameras, or an achromatic retarder for displays including organic light emitting diodes (OLED) and liquid crystal displays (LCD's).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The mesogenic groups do not comprise more than one unsaturated or aromatic ring. The compound (I) is selected from 10 compounds as given in the specification e.g. compound of formula (Ia) and (Ib).B'=group of formula (id);Z'=Z1;R=R1 (excluding P'-Sp-).    TECHNOLOGY FOCUS - POLYMERS - Preferred Film: The polymer film is a +A plate having a retardation dispersion of 0.7-0.98 at 0 degrees angle of incidence; or a +C plate having a retardation dispersion of 0.65-0.95 at 60 degrees angle of incidence. Preferred Definitions:    U1 and U2=selected from 5 groups as given in the specification e.g. cyclohexan-1,1,4-triyl, (1,3)dioxin-2,5,5-triyl, or (1,3)dioxan-2,2,5-triyl;    A1-A4=trans-1,4-cyclohexylene or 1,4-phenylene (optionally substituted by at least one L);    P'=selected from 23 groups as given in the specification e.g. CH3-CH=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, or (CH2=CH-CH2)2N-;    Sp=Sp'-X';    P'-Sp-=P'-Sp'-X'-;    Sp'=1-12C alkylene (optionally mono- or poly-substituted by F, CI, Br, I or CN, and where at least one non-adjacent CH2 group is optionally replaced, by -O-, -S-, -NH-, -NR0-, -SiR0R00-, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S-, -NR0-CO-O-, -O-CO-NR0-, -NR0-CO-NR0-, -CH=CH- or -C?=C- in such a manner that O and/or S atoms are not linked directly to one another);    X'=-O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR0-, -NR0-CO-, -NR0-CO-NR0-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR0-, -CY1=CY2-, -C?=C-, -CH=CH-COO-, -OCO-CH=CH- or single bond.    SPECIFIC COMPOUNDS - 2 Compounds are specified as the compound (I) comprises 1',1-4,4'-(1r,1'r,4r,4'r)-4,4'-(4,4'-(1,4-phenylenebis(ethyne-2,1-diyl))bis(4,1-phenylene))bis(ethyne-2,1-diyl)bis(4'-pentylbi(cyclohexane)-4,4-diyl)bis(oxy)bis(oxomethylene)bis(4,1-phenylene) 4-bis(4-(acryloyloxy)butyl) dicyclohexane-1,4-dicarboxylate (I'), and 1',1-4,4'-(1r,1'r,4r,4'r)-4,4'-(4,4'-(1,4-phenylenebis(ethyne-2,1-diyl))bis(4,1-phenylene))bis(ethyne-2,1-diyl)bis(4'-pentylbi(cyclohexane)-4,4-diyl)bis(oxy)bis(oxomethylene)bis(4,1-phenylene) 4-bis(6-(acryloyloxy)hexyl) dicyclohexane-1,4-dicarboxylate.    EXAMPLE - No suitable example given.